Thrust expansion device

A through-hole of a hydraulic chamber is provided on an input side of a thrust expansion device in accordance with rod diameters of various actuators on the input side, and an input rod of an air cylinder or the like is inserted therein. Thus, a thrust expansion mechanism operates. An input-side actuator attaching portion of the thrust expansion device is configured such that parts can be changed according to a fixing method of various actuators and a rod shape. It is possible to freely change a thrust expansion ratio by changing a cross sectional area of the input rod. A stroke of an output-side rod can be changed by changing an input stroke of the input-side actuator. According to the thrust expansion device, various inexpensive commercially available actuators can be easily attached and replaced by being separated and independent from the input-side actuator.

RELATED APPLICATIONS

This application claims priority to Japanese Patent Application Nos. 2018-205020, filed on Oct. 31, 2018 and 2019-175375 filed Sep. 26, 2019, the entire content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a thrust expansion device, and more particularly to a thrust expansion device that outputs an input pressure as an amplified thrust.

2. Description of the Related Art

A fluid pressure cylinder using a fluid such as air (gas) or oil (liquid) is used in many industrial fields.

The fluid pressure cylinder generates a thrust on a piston in a cylinder due to a pressure of a fluid such that the thrust can be a drive force of various types of mechanical actuation such as driving of a press or an actuator.

As such a fluid pressure cylinder, there is an air hydraulic cylinder that converts a pneumatic pressure to a hydraulic pressure inside the cylinder (Japanese Patent No. 4895342).

In the air hydraulic cylinder, the air cylinder (input side) and the hydraulic cylinder (output side) that expands the thrust are combined into a single cylinder, and an air piston that is driven by air is disposed on the input side in the cylinder. The hydraulic piston and an output rod that are driven by using, as an input, the output of the air piston are disposed on the output side.

However, in the air hydraulic cylinder described in Japanese Patent No. 4895342, since an input-side air cylinder unit and an output-side hydraulic cylinder unit (thrust expansion mechanism unit) are integrally formed, the output of the air cylinder unit, a size of the air cylinder, a stroke, and the like are fixed.

Therefore, in a case in which it is necessary to change the stroke of a different air cylinder unit or the like, it is not easy to replace only the air cylinder unit, so that it is necessary to replace the entire air hydraulic cylinder in practice.

SUMMARY OF THE INVENTION

According to an aspect of the invention, an object thereof is to make it possible to easily fix and replace an input-side actuator.

(1) According to a first aspect of the invention, there is provided a thrust expansion device that expands and outputs a thrust input from an input actuator by connecting the input actuator to an input side, the device including a cylinder; a fluid piston having a piston portion disposed in the cylinder and moving in a thrust direction in the cylinder, and an output rod connected to the piston portion; an output-side lid portion connected to one end side of the cylinder and provided with a through-hole in which the output rod moves in the thrust direction; an input-side lid portion connected to the other end side of the cylinder and provided with an input portion to which the thrust from the input actuator is input; fluid supply means for supplying a fluid into a fluid chamber partitioned by the cylinder, the piston portion, and the input-side lid portion; and fixing means for fixing the input actuator, which is disposed at least one location of the cylinder, the output-side lid portion, and the input-side lid portion.

(2) According to a second aspect of the invention, in the thrust expansion device of the first aspect, the input-side lid portion includes an input-side lid where a replacing input portion is formed at a center, and which is fixed to the cylinder, and a lid adaptor where the input portion is formed at a center, and which is disposed in the replacing input portion of the input-side lid, and is fixed in a replaceable manner.

(3) According to a third aspect of the invention, in the thrust expansion device of the first or second aspect, the fixing means includes fixing bolt holes formed in the input-side lid portion.

(4) According to a fourth aspect of the invention, in the thrust expansion device of the first, second, or third aspect, the fixing means includes fixing bolt holes formed on side surfaces of the input-side lid portion and the output-side lid portion.

(5) According to a fifth aspect of the invention, in the thrust expansion device of any one of the first to fourth aspects, the fluid piston includes a bottomed cavity portion extending from the piston portion to a middle of the output rod and forming a part of the fluid chamber.

(6) According to a sixth aspect of the invention, in the thrust expansion device of any one of the first to fifth aspects, the fixing means includes a bolt hole for fixing a fixing adaptor for fixing the input actuator via the fixing adaptor.

(7) According to a seventh aspect of the invention, in the thrust expansion device of the sixth aspect, the fixing means fixes the input actuator, at a position spaced apart from the input-side lid by a predetermined distance via the fixing adaptor.

(8) According to an eighth aspect of the invention, in the thrust expansion device of the seventh aspect, the fixing means fixes the input actuator where an adaptor rod is fixed to a front end of an input rod of the input actuator, at a position spaced apart by the predetermined distance via the fixing adaptor.

(9) According to a ninth aspect of the invention, in the thrust expansion device of the eighth aspect, the input portion formed on the input-side lid portion has a circular shape that matches a cross sectional shape of the adaptor rod fixed to the front end of the input actuator.

(10) According to a tenth aspect of the invention, in the thrust expansion device of any one of the first to seventh aspects, the input portion formed on the input-side lid portion has a circular shape that matches a cross sectional shape of an input rod of the input actuator.

(11) According to an eleventh aspect of the invention, in the thrust expansion device of any one of the first to tenth aspects, the input actuator to be fixed by the fixing means is an air cylinder or an electric cylinder.

(12) According to a twelfth aspect of the invention, in the thrust expansion device of the eleventh aspect, an input rod of the input actuator has a circular cross sectional shape with no level difference on an outer circumferential surface thereof.

(13) According to a thirteenth aspect of the invention, in the thrust expansion device of any one of the first to twelfth aspects, the output-side lid portion has a rotation stop member that restricts rotation of the piston with respect to the output-side lid portion.

(14) According to a fourteenth aspect of the invention, in the thrust expansion device of any one of the first to thirteenth aspects, the thrust expansion device further includes biasing means for applying a force to the fluid piston in a direction toward the input side.

(15) According to a fifteenth aspect of the invention, in the thrust expansion device of any one of the first to fourteenth aspects, the output-side lid portion includes an output-side lid where a replacing output portion is formed at a center and which is fixed to the cylinder, and a stop lid where the through-hole is formed at a center and which is disposed on the replacing output portion of the output-side lid and is fixed in a replaceable manner.

(16) According to a sixteenth aspect of the invention, in the thrust expansion device of the fifteenth aspect, the thrust expansion device further includes output fixing means for fixing an output attachment, disposed at least one location of the cylinder, the output-side lid portion, and the input-side lid portion, and receiving an expanded thrust output from the output rod.

(17) According to a seventeenth aspect of the invention, in the thrust expansion device of the sixteenth aspect, the thrust expansion device further includes the output attachment capable of replacing a working jig corresponding to a working step.

(18) According to an eighteenth aspect of the invention, in the thrust expansion device of the sixteenth aspect, the thrust expansion device further includes the output attachment capable of replacing gripping means for gripping a workpiece according to a workpiece shape.

(19) According to a nineteenth aspect of the invention, in the thrust expansion device of any one of the fifteenth to eighteenth aspects, the thrust expansion device further includes robot fixing means for fixing a robot adaptor for attaching a robot arm, which is disposed at least one location of the cylinder, the output-side lid portion, and the input-side lid portion.

(20) According to a twentieth aspect of the invention, in the thrust expansion device of any one of the first to nineteenth aspects, the fixing means fixes the input actuator so that an axis of an input rod of the input actuator that inputs a thrust to the input portion has a predetermined inclination angle with respect to an axis of the output rod.

(21) According to a twenty-first aspect of the invention, in the thrust expansion device of the twentieth aspect, the input-side lid portion is connected to the cylinder at the predetermined inclination angle with respect to the output-side lid portion.

(22) According to a twenty-second aspect of the invention, in the thrust expansion device of the twentieth or twenty-first aspect, the inclination angle is 90 degrees.

(23) According to a twenty-third aspect of the invention, there is provided a thrust expansion device including an input actuator having a cylindrical input rod; a cylinder; a fluid piston having a piston portion disposed in the cylinder and moving in a thrust direction in the cylinder, and an output rod connected to the piston portion; an output-side lid portion connected to one end side of the cylinder and provided with a through-hole in which the output rod moves in the thrust direction; an input-side lid portion connected to the other end side of the cylinder and provided with an input portion to which the thrust from the input actuator is input; fluid supply means for supplying a fluid into a fluid chamber partitioned by the cylinder, the piston portion, and the input-side lid portion; and fixing means for fixing the input actuator, which is disposed at least one location of the cylinder, the output-side lid portion, and the input-side lid portion. The input actuator is connected by inserting the input rod through the input-side lid portion to expand and output the thrust input from the input actuator.

According to the present invention, since the fixing means for fixing the input actuator to at least one location of the cylinder, the output-side lid portion, and the input-side lid portion is provided, various input-side actuators can be easily fixed and replaced.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(1) Outline of Embodiment

In a thrust expansion device1of the present embodiment, a portion constituting a thrust expansion function is separated from a so-called air hydraulic cylinder, which has an input function of inputting a thrust that is a source of the thrust to be output, and a thrust expansion function of expanding and outputting the input thrust as a fluid pressure using a Pascal's principle, and is formed independently.

The thrust expansion device1does not operate alone because there is no input in the device itself, and can be operated by assembling various input-side actuators directly or via an adaptor in order to obtain the thrust (input) to be expanded.

Specifically, an input port (through-hole41) of a fluid chamber (hydraulic chamber8) that matches rod diameters of various actuators on the input side is provided on the input side of the thrust expansion device1, a rod (input rod101or the like) of the input-side actuator is inserted into the input port, and thereby a thrust expansion mechanism operates.

An input-side actuator attaching portion of the thrust expansion device1is configured such that parts can be changed according to a fixing method of various actuators and a rod shape. It is possible to freely change a thrust expansion ratio by changing a cross sectional area of the input rod. A stroke of the output-side rod can be changed by changing an input stroke of the input-side actuator.

According to the thrust expansion device1, various commonly used cylinders can be easily attached and replaced by being separated and independent from the input-side actuator.

(2) Details of Embodiment

FIGS. 1A to 1Cillustrate a configuration of the thrust expansion device1according to the present embodiment, in whichFIG. 1Aillustrates a cross section in a thrust direction (direction of a centerline),FIG. 1Billustrates a side surface from a left side, andFIG. 1Cillustrates a side surface from a right side.

In all the drawings, the thrust output from the thrust expansion device1is described in an output direction from the left side to the right side of the drawings. Therefore, the left side of the drawing is referred to as the input side and the right side is referred to as the output side.

As illustrated inFIGS. 1A to 2, the thrust expansion device1includes a cylinder2that forms a part (circumferential surface) of a hydraulic chamber.

An input-side lid3is fixed to an end portion of the cylinder2on the input side, and a lid adaptor4that can be replaced according to the input-side actuator to be used is attached to a center of the input-side lid3. The input-side lid3and the lid adaptor4function as an input-side lid portion.

On the other hand, an output-side lid5is fixed to an end portion of the cylinder2on the output side, and a stop lid6is attached to a center of the output-side lid5.

A hydraulic piston7(fluid piston), which forms a part (one end surface in the thrust direction) of the hydraulic chamber and outputs an expanded thrust, is disposed inside the cylinder2.

A material of parts (excluding specific parts such as an O-ring and a sliding assistant ring) constituting the thrust expansion device1of the present embodiment is a metal such as aluminum, stainless steel, or iron.

As an example, the thrust expansion device1has sizes in which an outer diameter is about 70 mm and a stroke length of the output rod72is about 5 mm, however, the sizes may be larger or smaller than those described above.

Hereinafter, each of the cylinder2, the input-side lid3, the lid adaptor4, the output-side lid5, the stop lid6, and the hydraulic piston7will be described.

The cylinder2is formed in a cylindrical shape of which both end surfaces are open, a screw hole25is formed at the open end on the output side, and a screw hole26is formed at the open end on the input side.

The screw hole25is a screw hole for fixing the output-side lid5by a pressing bolt54, and female screws are formed inside. Screw holes25are formed at six locations on the same circumference corresponding to positions of the pressing bolts54illustrated inFIG. 1C.

The screw hole26is a screw hole for fixing the input-side lid3by a pressing bolt33, and female screws are formed inside. Screw holes26are formed at eight locations on the same circumference corresponding to positions of the pressing bolts33illustrated inFIG. 1A.

An oil filler21and an inlet/outlet hole23penetrate a cylindrical surface of the cylinder2.

The oil filler21is a through-hole for supplying oil into the hydraulic chamber8described later, and is closed by an oil filler plug22. Although one is illustrated in the drawing, two oil fillers21and two oil filler plugs22are provided on the same circumference of the cylinder2, and supply oil from either one of them into the hydraulic chamber8, and the other is used for air bleeding. A hydraulic pressure in the hydraulic chamber8may be measured by attaching a pressure sensor to any one of the oil fillers21.

The inlet/outlet hole23is a through-hole for inlet/outlet of air in a pneumatic chamber9described later, and is connected to an inlet/outlet24. The pneumatic chamber9, the inlet/outlet hole23, and the inlet/outlet24function as biasing means that applies a force to the fluid piston in a direction toward the input side.

The input-side lid3is formed in a plate shape having a large diameter flange portion and a small diameter portion. The input-side lid3has a small diameter portion accommodated in the cylinder2, and an end surface of the flange portion on the output side, abutting against the open end of the cylinder2.

Through-holes32are formed at eight locations in the flange portion of the input-side lid3. As illustrated inFIG. 1B, the eight pressing bolts33are inserted through the through-holes32and screwed into the screw holes26of the cylinder2, so that the input-side lid3is fixed to the cylinder2.

The flange portion of the input-side lid3is not circular as illustrated inFIG. 1B, but is formed in a square shape having four corners cut out concentrically. Therefore, four locations of an outer circumferential surface of the flange portion of the input-side lid3are formed in a flat shape, and a length between the flat surfaces facing each other is larger than the diameter of the cylinder2. The shape is the same as that of the flange portion of the output-side lid5described later.

Therefore, the thrust expansion device1can be stably mounted on a mounting table or the like by both surfaces positioned on the same surface of the input-side lid3and the output-side lid5. As will be described later, if extension adaptors142and162are fixed to the side surface of the thrust expansion device1, the extension adaptors142and162can be stably bolted to a flat surface of the flange portion by pressing bolts143,144,163, and164(SeeFIGS. 5A to 6B).

Although not illustrated in the drawing, screw holes (not illustrated) for the pressing bolts for fixing the extension adaptors142and162are formed, in the radial direction, on flat surface portions of an outer circumference of the flange portion in the input-side lid3and the output-side lid5.

At the center of the input-side lid3, a through-hole31(replacing input portion), in which the lid adaptor4is disposed, is formed (seeFIG. 2). The through-hole31of the input-side lid3is provided with a stepped portion by forming an inner diameter of the input side larger than that of the output side in accordance with the shape of the lid adaptor4, and a screw hole34is formed in the stepped portion in an output direction.

As illustrated inFIG. 1B, screw holes35are formed at four locations on the end surface of the input-side lid3on the input side. Since the screw hole35does not appear in the cross sections illustrated inFIGS. 1A and 2, the screw hole35is illustrated in a dotted line in the drawings. The screw hole35is a screw hole for bolting an input cylinder device such as an air cylinder to the thrust expansion device1.

Further, an outer circumferential groove38is formed over the entire circumference on the outer circumferential surface of the small diameter portion accommodated in the cylinder2in the input-side lid3(seeFIG. 2), and an O-ring39(seeFIG. 1A) is disposed in the outer circumferential groove38. The O-ring39seals oil in the hydraulic chamber8described later.

The lid adaptor4is disposed in the through-hole31of the input-side lid3, and the lid adaptor4is fixed to the input-side lid3by a pressing bolt44.

A through-hole41(input portion) is formed at the center of the lid adaptor4. The through-hole41is formed so that an inner diameter on the output side is larger than an inner diameter on the input side.

A guide bush42having the same thickness as a difference in inner diameter is disposed on the output side.

An outer diameter of the guide bush42is the same as the inner diameter of the through-hole41on the output side, and the inner diameter of the guide bush42is the same as the inner diameter of the through-hole41on the input side. However, the outer diameter of the guide bush42is formed to be larger by a press-fit interference (dimensional tolerance range) when the guide bush42is press-fitted into the through-hole41. Further, the inner diameter of the guide bush42is larger than the outer diameter of the input rod101to be inserted, and the input rod101is formed smaller than the inner diameter of the through-hole41on the input side within the dimensional tolerance range, so that the input rod101does not come into contact with the lid adaptor4. A length of the guide bush42in an axial direction is formed such that the end surface thereof on the output side is shorter than a length to the end surface of the lid adaptor4on the output side by the dimensional tolerance.

The guide bush42is a guide member that receives input rods of various cylinders attached to the thrust expansion device1and guides the movement of the input rod in a front-rear direction (input direction and output direction), on the inner circumferential surface.

In the flange portion of the lid adaptor4, through-holes43are formed at eight locations corresponding to the pressing bolts44at eight locations illustrated inFIG. 1B. The pressing bolt44is inserted into the through-hole43and screwed into the screw hole34of the input-side lid3, whereby the lid adaptor4is fixed to the input-side lid3.

The lid adaptor4is appropriately replaced in accordance with the size of the cylinder device disposed on the input side, particularly the size of the input rod inserted into the through-hole41. The inner diameters of the through-hole41and the guide bush42of the lid adaptor4to be replaced, and a size of an O-ring47described later are selected according to the input rod diameter of the cylinder device.

The replacement of the lid adaptor4is performed by removing the pressing bolt44.

According to the present embodiment, by providing the lid adaptor4corresponding to the cylinder on the input side separately from the input-side lid3, the cylinder can be easily replaced to different types of cylinders on the input side while the hydraulic piston7is accommodated inside thereof.

The input-side lid3and the lid adaptor4are not separated, but the input-side lid3that is integrally formed is used, is removed by the pressing bolt33, and may be replaced to an input-side lid3matched to the input rod diameter of the cylinder device.

Although not illustrated inFIGS. 1A to 2, according to the lid adaptor4, for example, as illustrated inFIG. 3D, a plurality screw holes45for attaching the cylinder device to the input side of the thrust expansion device1are formed.

An inner circumferential groove46is formed over the entire circumference of the inner circumferential surface of the through-hole41on the input side in the lid adaptor4(seeFIG. 2), and the O-ring47(seeFIG. 1A) is disposed in the inner circumferential groove46.

An outer circumferential groove48is formed over the entire circumference of the outer circumferential surface of the small diameter portion in the lid adaptor4(seeFIG. 2), and the O-ring49(seeFIG. 1A) is disposed in the outer circumferential groove48.

Both the O-ring47and the O-ring49seal oil in the hydraulic chamber described later.

On the other hand, the output-side lid5is disposed on the output side of the cylinder2.

The output-side lid5is formed in a plate shape having a small diameter portion and a large diameter flange portion. The small diameter portion of the output-side lid5is accommodated in the cylinder2, and an end surface of the flange portion on the input side abuts against the open end of the cylinder2.

An outer circumferential groove58is formed on the entire circumference of the outer circumferential surface of the small diameter portion in the output-side lid5(seeFIG. 2), and an O-ring59for sealing the air in the pneumatic chamber9is disposed in the outer circumferential groove58(seeFIG. 1A).

Through-holes53are formed at six locations in the flange portion of the output-side lid5. As illustrated inFIG. 1C, the six pressing bolts54are inserted into the through-holes53and screwed into the screw holes25of the cylinder2, so that the output-side lid5is fixed to the cylinder2.

The flange portion of the output-side lid5is formed in a square shape with four corners concentrically cut out as in the case of the input-side lid3(seeFIGS. 1B and 1C).

As illustrated inFIG. 2, a through-hole50in which the stop lid6is disposed is formed at the center of the output-side lid5. A small inner diameter portion, a medium inner diameter portion, and a large inner diameter portion from the input side to the output side are formed on the inner circumferential surface of the through-hole50of the output-side lid5.

In the stepped portion formed by the medium inner diameter portion and the large inner diameter portion, screw holes52directed in the input direction are formed at six locations. The screw holes52are provided for fixing the stop lid6described later to the output-side lid5.

A guide bush51having the same thickness as a difference between the small inner diameter portion and the medium inner diameter portion is disposed in the medium inner diameter portion of the through-hole50of the output-side lid5. A length of the guide bush51in the axial direction is the same as the length of the medium inner diameter portion in the axial direction. An outer diameter and an inner diameter of the guide bush51are respectively the same as the inner diameter of the medium inner diameter portion and the inner diameter of the small inner diameter portion of the through-hole50.

However, the outer diameter and inner diameter of the guide bush51are formed so as to have a larger outer diameter by a press-fit amount within a range of a dimensional tolerance as in the case of the guide bush42, and the inner diameter is formed smaller within the range of the dimensional tolerance. Therefore, the inserted output rod72does not conic in contact with other than the guide bush51. The length of the guide bush51in the axial direction is also shorter than that of the medium inner diameter portion in the range of the dimensional tolerance.

The guide bush51is a guide member that receives the output rod72of the hydraulic piston7disposed in the cylinder2on the inner circumferential surface thereof and guides the movement of the input rod in the front-rear direction (input direction and output direction).

On the outside of the medium inner diameter portion of the through-hole50of the output-side lid5, a hole55is formed at one location and holes57aare formed at six locations at positions that do not interfere with each other. The number of holes55and holes57can be set arbitrarily.

A rotation preventing pin75slides inside the hole55in the input/output direction in accordance with the movement of the hydraulic piston7described later.

An end portion of the coil spring57on the output side is inserted and is fixed into and to the hole57a. The end portion of the coil spring57(biasing means) on the input side abuts against the end surface of the piston portion71on the output side.

As illustrated inFIG. 1C, the screw holes56are formed at six locations on the end surface of the output side lid5on output side. The screw hole56is provided for attaching various members to the thrust expansion device1on output side.

In the through-hole50in the output-side lid5, a stop lid6for fixing the guide bush51disposed in the medium inner diameter portion is disposed in the large inner diameter portion.

A through-hole61into which the output rod72is inserted is formed at the center of the stop lid6. An inner circumferential groove64is formed in the through-hole61over the entire circumference (seeFIG. 2), and a dust seal65(seeFIG. 1A) is disposed in the inner circumferential groove64.

The dust seal65prevents foreign dust and foreign matters adhering to the output rod72from entering the thrust expansion device1when the output rod72slides. Through-holes62are formed at six locations outside the through-hole61. As illustrated inFIG. 1C, six pressing bolts63are inserted into the through-holes62and screwed into the screw holes52of the output-side lid5, so that the stop lid6is fixed to the output-side lid5.

The hydraulic piston7includes a piston portion71and an output rod72extending from the center of the piston portion71in the output direction. The piston portion71is disposed in the cylinder2, and together with the cylinder2, an input side surface forms a part of the inner wall of the hydraulic chamber8, and an output side surface forms a part of the pneumatic chamber9.

An outer circumferential groove78is formed over the entire circumference of the outer circumferential surface of the piston portion71(seeFIG. 2), and an O-ring79(seeFIG. 1A) that seals between the hydraulic chamber8and the pneumatic chamber9is disposed in the outer circumferential groove78.

A pin hole74and a pin hole76are formed at locations corresponding to the hole55and the hole57aof the output-side lid5on the end surface of the piston portion71on the output side.

In the pin hole74, one end side of the rotation preventing pin75is fixed by press-fitting, and the other end side is slidably inserted into the output-side lid5. The rotation preventing pin75restricts the rotation of the piston portion71according to the movement in the input/output direction.

One end side of the guide pin77is fixed to the pin hole76by press-fitting, and the output side is inserted into the coil spring57from the press-fitted portion so as to guide the extension and contraction of the coil spring57. In the present embodiment, six coil springs57are disposed circumferentially, but one coil spring may be provided. In this case, the output rod72is inserted into the inner diameter of the coil spring, the end portion of the coil spring on the input side may abut against the end surface of the piston portion71on the output side, and the end portion of the coil spring on the output side may abut against the end surface of the output-side lid5in the input side, with an appropriate positioning groove or the like.

The rotation preventing pin75and the coil spring57are an example of a rotation stop member.

A bottomed cavity portion73that does not penetrate in the axial direction from the input side is formed at the center of the hydraulic piston7. An inside of the cavity portion73also constitutes a part of the hydraulic chamber8, and the input rod of the cylinder connected to the thrust expansion device1enters and leaves the inside of the cavity portion73.

A bolt hole72ais formed on the output side of the output rod72of the hydraulic piston7from the end surface thereof in the input direction. The bolt hole72ais provided, for example, for attaching various tools such as punches for punching used in a press working or the like.

Next, the use of the thrust expansion device1configured as described above will be described.

When the thrust expansion device1of the present embodiment is used, various input actuators are attached to the input side to be used.

FIGS. 3A to 3Dillustrate first and second usage examples in which the air cylinder that functions as the input actuator is attached to the thrust expansion device1. InFIGS. 3A to 3D, in order to explain an internal state of the thrust expansion device1, it illustrates the cross section.

In the first usage example ofFIG. 3A, an air cylinder100is illustrated in an attached state,FIG. 3Billustrates the left side, andFIG. 3Cillustrates an operation state of the thrust expansion device1by the air cylinder100.

As illustrated inFIG. 3A, the air cylinder100includes a cylindrical input rod101and inlet/outlet holes102and103. The air cylinder100is configured such that the front end of the input rod101moves in the output direction and the input direction by supplying and exhausting air from the inlet/outlet holes102and103.

In addition, as illustrated inFIG. 3B, the air cylinder100is formed such that an external shape of the main body portion is square, and through-holes are formed in the four corners of the main body portion so as to penetrate in the axial direction.

When the air cylinder100is attached, four pressing bolts109passed through the through-holes of the main body portion are screwed into the screw holes35of the input-side lid3in a state in which the front end of the input rod101is inserted into the through-hole41formed in the input-side lid3of the thrust expansion device1, and thereby the air cylinder100is fixed to the thrust expansion device1.

After the air cylinder100is attached, the oil filler plug22is removed from the cylinder2and oil is supplied from the oil filler21.

In addition, in the thrust expansion device1of the embodiment, oil, such as hydraulic fluid which is easily available and is an incompressible fluid, is used as a fluid used for a portion which outputs the fluid as amplified fluid pressure (thrust). However, it is also possible to use a fluid gas, liquid, or gel substance as the fluid to be used. In this case, the hydraulic chamber8is filled with the fluid.

InFIGS. 3A to 6B, an oil-filled region is illustrated by a solid color so that a state of the hydraulic chamber8filled with oil can be easily understood.

When using the thrust expansion device1to which the air cylinder100is attached, the inlet/outlet24of the thrust expansion device1and the inlet/outlet hole103of the air cylinder100are opened inFIG. 3A, so that the internal air can escape.

In this state, as illustrated inFIG. 3C, air is supplied from the inlet/outlet hole102(indicated by a thick arrow), whereby the input rod101of the air cylinder100moves in the output direction. The internal air escapes from the inlet/outlet24and the inlet/outlet hole103as indicated by a thick arrow, and enters the hydraulic chamber8.

Therefore, the oil in a cavity portion73of the output rod72passes through the outer circumferential side of the input rod101and moves between the input-side lid3, the lid adaptor4, and the piston portion71. The piston portion71and the output rod72move to the output side by a hydraulic stroke OS (seeFIGS. 3A and 3C).

From a front end of the output rod72, a thrust Fp1amplified (expanded) by the hydraulic pressure is output with respect to the thrust of the air cylinder100, that is, a thrust Fi from a front end of the input rod101.

Here, when an area of the front end surface of the input rod101is S1, and an area (area including a bottom surface of the cavity portion73and the same as the radial sectional area of the cylinder2) of the piston portion71is S2, a force received by the piston portion71from the oil in the hydraulic chamber8, that is, the thrust Fp output from the front end of the output rod72is expressed by the following equation (1).
Fp1=(Fi/S1)×S2=Fi×(S2/S1)  Equation (1)

According to the thrust expansion device1of the present embodiment, since a relationship of S1<S2is satisfied, the output rod72can output the thrust Fp expanded with respect to the thrust Fi from the input rod101.

Further, the air cylinder100can be easily attached to the thrust expansion device1.

A case of returning from the state ofFIG. 3Cin which the expanded thrust is output from the thrust expansion device1to the initial state illustrated toFIG. 3Ais as follows.

That is, by opening the inlet/outlet hole102and supplying air from the inlet/outlet hole103, the input rod101of the air cylinder100retreats to the input side.

Therefore, in the hydraulic chamber8, a space corresponding to a volume in which the input rod101was placed is restored, and the space of the through-hole41is also restored. In the hydraulic chamber8, no fluid flows in and out from the outside. Therefore, the oil in the hydraulic chamber8flows into the restored space portion, and a negative pressure to the input side is generated in the piston portion71. Since the atmospheric pressure is applied to the pneumatic chamber9, the piston portion71moves to the input side. In this case, a biasing force of the coil spring57assists the movement toward the input side.

Here, in a case of returning to the initial state more reliably, air may be supplied from the inlet/outlet hole103and air may be supplied to the pneumatic chamber9from the inlet/outlet24of the thrust expansion device1that has been opened.

The rotation of the piston portion71can be suppressed by the rotation preventing pin75with respect to the movement in the output direction and the movement in the input direction. Further, since the coil spring57extends and contracts along the guide pin77, it is possible to apply a biasing force to the piston portion71in the axial direction.

FIG. 3Dillustrates an operation state (corresponding toFIG. 3C) of a second usage example.

The second usage example inFIG. 3Dis an example of a case in which a small air cylinder120smaller than the air cylinder100of the first usage example is attached.

The small air cylinder120has a smaller external size of a main body and a smaller diameter of an input rod121than those of the air cylinder100.

Since the external size of the main body is small, a pressing bolt129for fixing the small air cylinder120to the thrust expansion device1is not screwed into the screw hole35of the input-side lid3but is screwed into the screw hole45formed in the lid adaptor4.

When initially attaching the small air cylinder120to the thrust expansion device1, the through-hole41matched with a diameter of the input rod121of the small air cylinder120and the lid adaptor4of the guide bush42are used.

On the other hand, as illustrated inFIG. 3A, a case of replacing the air cylinder100attached to the thrust expansion device1is as follows.

That is, after removing the oil filler plug22and draining the oil in the hydraulic chamber8, the air cylinder100is removed, and the pressing bolt44is removed to remove the lid adaptor4from the input-side lid3.

Thereafter, the lid adaptor4for the small air cylinder120is replaced, and is fixed to the input-side lid3by the pressing bolt44. Thereafter, the small air cylinder120is screwed into the screw hole45by the pressing bolt129and is fixed to the thrust expansion device1. Further, the cylinder2is filled with the oil from the oil filler21and then the oil filler plug22is put.

As described above, in the thrust expansion device1of the present embodiment, another cylinder having a different input rod diameter can be easily replaced by replacing the lid adaptor4.

A stroke of the small air cylinder120is longer than that of the input rod101of the air cylinder100by SS. Therefore, the input rod121enters the cavity portion73of the output rod72as much as the SS, but the length of the cavity portion73is sufficiently secured in forward so as to cope with it. Therefore, even if the air cylinder100is changed to the small air cylinder120, it is not necessary to replace the output rod72.

When an area of the piston portion71is the same as S2, an end surface area of the input rod121is S3, and the thrust of the small air cylinder120, that is, the thrust from the front end of the input rod121is Fi2, the output Fp2from the output rod72is expressed by the following equation (2).
Fp2=(Fi2/S3)×S2=Fi2×(S2/S3)  Equation (2)

In Equation (2) and Equation (1), when Fi1=Fi2, since S1>S3, it becomes Fp2>Fp1, and a large amplified output can be obtained for the same thrust input.

Next, a third usage example of the thrust expansion device1is described.

FIGS. 4A and 4Billustrate a usage state for the third usage example.

The third usage example is an example of a case in which an electric cylinder130is attached as a cylinder attached to the thrust expansion device1.

The electric cylinder130illustrated inFIG. 4Adiffers from the air cylinder100and the small air cylinder120described with reference toFIGS. 3A to 3D, and is an example in a case in which there is no through-hole penetrating the main body, or a case in which the positions of the screw hole35and the screw hole45do not fit.

In this case, as illustrated inFIG. 4A, the electric cylinder130is fixed to the thrust expansion device1via an adaptor133.

Here, in a case in which the electric cylinder130can be directly attached to the input-side lid3or the lid adaptor4, the electric cylinder130may be directly attached without using the adaptor133. InFIGS. 3A to 3D, in a case in which the air cylinder cannot be directly attached to the input-side lid3or the lid adaptor4, an adaptor corresponding to the adaptor133may be provided to fix to the thrust expansion device1. The adaptor133is provided with a through-hole134into which a cylindrical input rod131is inserted at the center, a through-hole is formed corresponding to a position of the screw hole35of the input-side lid3, and a through-hole is formed for fixing to the electric cylinder130.

The input rod131passes through the through-hole134of the adaptor133, and the electric cylinder130is attached to the adaptor133by a pressing bolt135. Then, the electric cylinder130is fixed to the thrust expansion device1via the adaptor133by screwing a pressing bolt136into the screw hole35of the lid adaptor4.

In the sectional view ofFIGS. 4A and 4B, since the cross section is changed middle to display the pressing bolt136, the display position of the screw hole35is different from that inFIGS. 1A to 1C, but the actual position of the screw hole35is formed at the same position as illustrated inFIG. 1B.

When a cylinder device having a main body of which an external shape is larger than that of the input-side lid3is attached, an adaptor having a diameter larger than that of the input-side lid3is used. After the adaptor is bolted to the input-side lid3(or the lid adaptor4), the cylinder is fixed by a pressing bolt outside the adaptor from the input-side lid3.

The electric cylinder130is provided with a power feeding unit139and controls energization of a built-in motor, so that the input rod131can be taken in and out.

By making the inlet/outlet24is in an open state and driving the electric cylinder130to move the input rod131in the output direction. Therefore, as illustrated inFIG. 4B, the input rod131enters the inside of the cavity portion73(hydraulic chamber8), and the output rod72forwards by the hydraulic stroke OS and outputs the expanded thrust from the front end of the output rod72.

In this case, the thrust output from the front end of the output rod72is obtained according to Equation (1). The principle of thrust expansion is the same as that of the air cylinder.

As described above, according to the thrust expansion device1of the present embodiment, the electric cylinder130can be easily attached. Therefore, for the input-side actuator, it is possible to optimally select the air drive or electric drive according to the use environment of the device.

In the present embodiment, as the input-side actuator, an air-driven actuator is illustrated inFIGS. 3A to 3Dand an electrically driven actuator is illustrated inFIGS. 4A and 4B, but as long as a cylinder-type linear motion actuator having one equivalent to the input rod131is used, anything may be used, and as long as the input-side actuator can be attached to the thrust expansion device1, the thrust of the input actuator can be expanded and output.

When returning from the output state illustrated inFIG. 4Bto the initial state illustrated inFIG. 4A, the electric cylinder130may be driven to retreat the input rod131in the input direction.

Therefore, the piston portion71moves to the input side by the negative pressure due to the movement of the oil in the hydraulic chamber8to the input side and the biasing force of the coil spring57.

Here, in a case of returning to the initial state more reliably, air may be supplied to the pneumatic chamber9from the inlet/outlet24of the thrust expansion device1that has been in the opened state.

Next, fourth and fifth usage examples of the thrust expansion device1will be described.

Whereas the input rod of each cylinder device described in the first to third usage examples has the cylindrical shape, a cylinder device attached to the thrust expansion device1in the fourth and fifth usage examples is an example of a case in which the input rod does not have a single cylindrical shape.

Many of front ends of general cylinder rods have male or female screws at the rod front end, and one or several two-surface width cuts is made on the outer circumferential surface of the input rod to hang a workpiece tool (for example, a spanner) when parts are assembled using the screws. In a case of a non-cylindrical shape such as the two-surface width cut or male screw portion, the oil in the hydraulic chamber8cannot be sealed with an O-ring or the like in a range where the portion slides, so that a seal portion cannot be disposed.

Even in a case of a cylindrical shape, there is a case in which the input rod has a stepped shape with a small diameter from a middle of the front end portion, but in the same manner, an O-ring cannot be provided in a range where the stepped portion slides.

It is also possible to insert the irregularly shaped portions deep inside the hydraulic chamber8so that they do not slide on the O-ring portion. However, in that case, it is necessary to lengthen the cavity portion73, which not only increases the size, but also requires replacement of the output rod72in some cases. Moreover, when inserting the irregularly shaped portion, the O-ring may be damaged and it cannot assemble easily.

Therefore, in the following usage example, a case will be described in which the actuator having these irregularly shaped portions is configured to be easily coupled to the thrust expansion device1.

FIGS. 5A and 5Billustrate a state in which an air cylinder140having the irregularly shaped portion at the front end portion of the input rod is attached to the thrust expansion device1, as a fourth usage example.

The air cylinder140illustrated inFIG. 5Ais provided with a square pole-shaped input rod141that is not circular in cross section, for example, in which the two-surface width cut portions are formed at two locations with 90° phase, and an attachment screw hole is formed at the center of the front end.

Since the air cylinder140cannot be directly attached to the thrust expansion device1, the air cylinder140is attached by an adaptor rod150and an extension adaptor142.

The adaptor rod150has a bolt formed at an end portion on the input side, and is screwed into a screw hole at the front end of the input rod141. An external shape of the adaptor rod150is the same as the inner diameter of the lid adaptor4in the thrust expansion device1.

Since the input rod141becomes longer as much as the adaptor rod150is attached, in the fourth usage example, the air cylinder140is attached to the thrust expansion device1by the extension adaptor142.

The extension adaptor142includes a plate-like portion142aand an extension portion142bextending from the plate-like portion142ain a right angle direction.

In the extension portion142b, through-holes for fixing by the pressing bolts143and144are formed at positions corresponding to screw holes formed in the output-side lid5and the input-side lid3of the thrust expansion device1.

The through-hole for the pressing bolt143and the screw hole of the output-side lid5are formed at two locations outside avoiding the interference by the pressing bolt54illustrated inFIG. 1C. The through-hole for the pressing bolt144and the screw hole of the input-side lid3are formed at two locations outside avoiding the interference by the pressing bolts33and33illustrated inFIG. 1B.

On the other hand, the plate-like portion142ais provided with a through-hole into which the input rod141is inserted at a center, and concentric circular through-holes are formed at four locations on the outside thereof.

The adaptor rod150has a single cylindrical outer circumferential surface that is a stroke or more of the air cylinder140, and is designed according to the shape of the input rod141. For example, if the front end of the input rod141is the male screws, the adaptor rod150is provided with the female screws.

When attaching the air cylinder140to the thrust expansion device1, the adaptor rod150is attached to the input rod141, and the plate-like portion142ais attached to the air cylinder140by the pressing bolt145. In this state, the front end of the adaptor rod150is inserted into the through-hole of the lid adaptor4, and the extension portion142bis fixed to the thrust expansion device1by the pressing bolts143and144.

Subsequent filling of the hydraulic chamber8with oil is the same as those in other usage examples.

The operation for outputting the expanded thrust from the output rod72in the operation state ofFIG. 5Band the operation for returning to the initial state by the operation of driving the thrust expansion device1, to which the air cylinder140is attached, are the same as those in the first usage example.

FIGS. 6A and 6Billustrate a state in which an electric cylinder160is attached to the thrust expansion device1, as a fifth usage example.

The electric cylinder160illustrated inFIG. 6Aincludes a power feeding unit169, and a built-in motor is controlled by power feeding from the power feeding unit169, so that the input rod161can be taken in and out.

The input rod161of the electric cylinder160is not circular in cross section, and has a square pole-shaped front end in which the two-surface width cut portions are formed at two locations with 90° phase on the outer circumferential surface, and an attachment screw hole is formed at the center of the front end.

Since the electric cylinder160cannot also be directly attached to the thrust expansion device1like the air cylinder140, the electric cylinder160is attached by the adaptor rod150and the extension adaptor162. The adaptor rod150is the same as that used in the fourth usage example.

Since the input rod161becomes long as much as the adaptor rod150is attached, in the fifth usage example, the electric cylinder160is attached to the thrust expansion device1by the extension adaptor162.

The extension adaptor162is formed in a plate shape, and as illustrated inFIGS. 6A and 6B, a stepped portion162acorresponding to a size difference in the radial direction between the thrust expansion device1and the electric cylinder160is formed. In the example illustrated inFIGS. 6A and 6B, the thrust expansion device1is larger, and accordingly, the output side is formed thinner than the input side by the stepped portion162a.

On the output side from the stepped portion162a, through-holes for fixing by the pressing bolts163and164are formed at positions corresponding to the screw holes formed in the output-side lid5and the input-side lid3of the thrust expansion device1. The through-holes for the pressing bolts163and164, and the screw holes in the output-side lid5and the input-side lid3are formed at two locations outside avoiding the interference by the pressing bolts54and the pressing bolts33illustrated inFIGS. 1C and 1B.

On the other hand, through-holes for the pressing bolts165and166are formed on the input side from the stepped portion162a.

When attaching the electric cylinder160to the thrust expansion device1, the adaptor rod150is attached to the input rod161, and the extension adaptor162is attached to the electric cylinder160by the pressing bolts165and166. In this state, the front end of the adaptor rod150is inserted into the through-hole of the lid adaptor4, and the extension adaptor162is fixed to the thrust expansion device1by the pressing bolts163and164.

Subsequent filling of the hydraulic chamber8with oil is the same as those in other usage examples.

The operation for outputting the expanded thrust from the output rod72in the operation state ofFIG. 6Band the operation for returning to the initial state by the operation of driving the thrust expansion device1, to which the electric cylinder160is attached, are the same as that in the third usage example.

Next, a sixth usage example will be described.

FIGS. 7A to 7Fillustrate a state in which an air cylinder100, an articulated robot arm200, and an output attachment300are attached to the thrust expansion device1as the sixth usage example.

FIG. 7Aillustrates a state viewed from the front of the thrust expansion device1,FIG. 7Billustrates a state viewed from above,FIG. 7Cillustrates a state viewed from below,FIG. 7Dillustrates a state viewed from a side surface,FIG. 7Eillustrates a cross section taken along line A-A, andFIG. 7Fillustrates a cross section taken along line B-B, respectively.

In addition,FIGS. 7A and 7Billustrate a state in which the articulated robot arm200is attached, and the others illustrate a state in which the articulated robot arm200is not attached.

Further, inFIG. 7A, as in the first to fifth usage examples described inFIGS. 3A to 6B, the thrust expansion device1is illustrated in a cross section for explaining an internal state.

Hereinafter, in each usage example and each embodiment, the articulated robot arm200in an articulated robot will be described as an example. It is also possible to attach the thrust expansion device1to various robots such as a robot that moves only in a linear direction and a SCARA type robot that moves by rotating an arm.

In the sixth usage example, a state in which the air cylinder100is connected is illustrated, but the cylinder connected to the input side is not particularly limited, and any one of the cylinders described in the first to fifth usage examples can be connected.

As illustrated inFIG. 7D, the air cylinder100connected to the thrust expansion device1of the sixth usage example has two rails disposed on the outer circumferential surface of the cylinder2in the axial direction, an input-side sensor100A disposed on one side, and an output-side sensor100B disposed on the other side.

The input-side sensor100A and the output-side sensor100B are sensors for detecting a position of a magnet (not illustrated) disposed on the piston to which the input rod101(seeFIGS. 3A to 3D) of the air cylinder100is connected. By detecting the position of the piston of the air cylinder100, it is possible to confirm how much the input rod101was inserted into the hydraulic chamber8of the thrust expansion device1and to confirm a movement distance of the output rod72. The input-side sensor100A and the output-side sensor100B can be disposed in the air cylinders described in the other usage examples.

As illustrated inFIGS. 7A to 7F, when attaching the thrust expansion device1to the articulated robot arm200, a robot adaptor201is assembled on the side surface and the thrust expansion device1is fixed via the robot adaptor201.

As illustrated inFIGS. 7A and 7B, the robot adaptor201has a rectangular shape, and bolt holes for the pressing bolts206are formed at four corners thereof. The robot adaptor201is fixed to the input-side lid3and the output-side lid5by the pressing bolts206.

For the bolt holes of the input-side lid3and the output-side lid5for fixing the robot adaptor201by the pressing bolts206, the extension adaptors142and162described in the fourth usage example and the fifth usage example are fixed by using bolt holes for fixing the pressing bolts143,144,163, and164. However, bolt holes dedicated to the pressing bolts206for fixing the robot adaptor201may be formed in the input-side lid3and the output-side lid5.

At the front end of the articulated robot arm200, a positioning recessed portion for fixing the robot adaptor201and fixing bolt holes (four locations) are formed.

A positioning pin202for positioning the robot adaptor201and the articulated robot arm200is press-fitted on a surface of the robot adaptor201opposite to a side facing the thrust expansion device1.

As illustrated inFIG. 7D, the robot adaptor201is formed in a rectangular shape, and has bolt holes at four locations for fixing the articulated robot arm200by bolts204on a concentric circle with the positioning pin202.

Bolt holes for fixing to the input-side lid3and the output-side lid5of the thrust expansion device1by the pressing bolts206are formed at four corners of the robot adaptor201.

When the thrust expansion device1is attached to the articulated robot arm200, the following procedure is used.

First, the robot adaptor201is attached to the front end of the articulated robot arm200using the positioning pin202and is fixed by the four bolts204.

Next, the thrust expansion device1is fixed to the robot adaptor201by the four pressing bolts206using the input-side lid3and the output-side lid5.

On the other hand, the output attachment300for use in pressing, caulking, or the like is attached to the output side of the thrust expansion device1.

As illustrated inFIGS. 7A and 7C, the output attachment300includes an attachment base portion302fixed to the output-side lid5of the thrust expansion device1, an arm portion303, and an output receiving portion304which are formed integrally with the attachment base portion302.

The attachment base portion302is formed in a flat plate shape, and a through-hole into which the output rod72of the thrust expansion device1is inserted is formed at a center thereof. On the outer circumferential side of the through-hole, through-holes for attaching the attachment base portion302to the output-side lid5are formed at six locations, and are fixed by the pressing bolts306.

The pressing bolts306for fixing the attachment base portion302are fixed by the screw holes56(seeFIGS. 1A to 2) formed in the bolt hole of the output-side lid5.

The arm portion303has a square pole shape, and extends in a direction orthogonal to the attachment base portion302at a position outside the central through-hole in the attachment base portion302. The output receiving portion304is integrally formed on the front end side of the arm portion303so as to face the output rod72of the thrust expansion device1disposed at the center of the attachment base portion302in an orthogonal direction.

Similarly to the bolt hole72afor attaching various tools formed at the front end of the output rod72, a bolt hole for attaching various tools is also formed at a position facing the output receiving portion304.

In the output attachment300of the example illustrated inFIGS. 7A to 7F, a caulking tool72A and a caulking tool308A for caulking are respectively attached to the output rod72and the output receiving portion304.

Next, propagation of the pressing force output from the thrust expansion device1in the sixth usage example will be described.

FIGS. 8A and 8Bare explanatory views of the propagation of the pressing force output when a caulking process of a workpiece WA is performed by the thrust expansion device1attached to the articulated robot arm200, in whichFIG. 8Aillustrates a case in which the output attachment300is not attached to the output side, andFIG. 8Billustrates a case in which the output attachment300is attached to the output-side lid5.FIG. 8Billustrates the output side from a dotted line M in cross section.

The workpiece WA is the same as a workpiece WA ofFIGS. 9A to 9Idescribed later.

As illustrated inFIG. 8A, the workpiece WA is disposed on a caulking tool308A attached to a cradle309, and an amplified pressing force PT is output from the output rod72(caulking tool72A attached to the output rod72).

An operation of outputting the amplified pressing force P1(=thrust Fp) from the output rod72is as described inFIGS. 3A and 3B.

A load (=pressing force P1) applied to the workpiece WA from the output rod72(caulking tool72A) of the thrust expansion device1propagates to the cradle309as a pressing force P2, and then propagates to a grounding surface of the cradle309.

On the other hand, the output rod72receives a reaction force P3equal to the pressing force PT output to the workpiece WA, from the workpiece WA. The reaction force P3propagates to a body (cylinder2, input-side lid3, and output-side lid5) of the thrust expansion device1as a reaction force P4, and further, a reaction force P5propagates to the articulated robot arm200via the robot adaptor201.

As described above, in order to perform a process such as pressing, caulking, drilling (punching), or the like without attaching the output attachment300to the thrust expansion device1, it is also propagated to the articulated robot arm200. For example, when a thrust of 10 kN is output from the thrust expansion device1, the articulated robot arm200is required to have a capacity (loadable weight>propagating reaction force P5+weight of the thrust expansion device1) sufficient to receive a reaction force of propagating 10 kN.

However, the articulated robot arm200having a loadable weight of 10 kN or more is large in size and is not suitable for working a small workpiece from the viewpoint of equipment cost and installation space.

Next, the propagation of the pressing force when the output attachment300is attached to the thrust expansion device1described in the sixth usage example, and pressing or the like is performed will be described.

As illustrated inFIG. 8B, a load (=pressing force Q1=P1) applied to the workpiece WA from the output rod72(caulking tool72A) of the thrust expansion device1propagates from the output receiving portion304of the output attachment300to the arm portion303as a pressing force Q2, and further propagates to the attachment base portion302(=Q3).

On the other hand, the output rod72receives a reaction force Q4equal to the pressing force Q1output to the workpiece WA, from the workpiece WA, and the reaction force Q4propagates from the body (cylinder2, input-side lid3, and output-side lid5) of the thrust expansion device1to the attachment base portion302(=Q5).

As illustrated inFIG. 8B, the pressing force Q3and the reaction force Q5propagated to the attachment base portion302of the output attachment300are equal in magnitude and opposite in direction, so that the pressing force Q3and the reaction force Q5are canceled each other inside the output attachment300(and the thrust expansion device1).

As described above, even when a large thrust is output from the output rod72of the thrust expansion device1, the pressing force is canceled inside including the output attachment300and the reaction force does not propagate to the articulated robot arm200.

Therefore, unlike the case ofFIG. 8Ain which the output attachment300is not attached, the articulated robot only needs to consider a weight of a unit to be mounted. For example, even in an articulated robot having a loadable weight of about 4 kg (however, weight of the mounting unit including the thrust expansion device1is less than 4 kg), it is possible to output a thrust of 10 kN or more from the thrust expansion device1and perform working such as pressing, caulking, or drilling.

In the related art, in a case of mainly metal working, a working apparatus is heavy and large because it requires a large working thrust, and is fixed to be used because it cannot be easily moved. Therefore, it has been necessary to move the workpiece to the working apparatus, to process the workpiece, and to return the workpiece to an original position after working.

On the other hand, according to the working apparatus using the thrust expansion device1described in the sixth usage example, since the thrust expansion device1is small and light in weight with respect to the output, the thrust expansion device1is fixed to the articulated robot arm200and moved by the articulated robot, so that it is possible to perform various processes such as caulking and drilling. A small articulated robot with a small loadable weight can also be used. Therefore, without moving the workpieces installed on a line, the working apparatus using the output attachment300and the thrust expansion device1is moved to a workpiece installation location by the articulated robot arm200, and working such as drilling, or caulking can be performed.

As described above, according to the sixth usage example, without moving the workpiece from a production line, it is possible to process the workpiece on the line by moving the working apparatus using the output attachment300and the thrust expansion device1, and in particular, if the workpiece is large in size, the work space can be reduced and the effect can be increased.

Next, various types of working using the output attachment300capable of canceling the thrust to be output, in the inside, will be described.

FIGS. 9A to 9Iare sectional views for explaining various types of working such as caulking, drilling, and pressing according to the sixth usage example of the thrust expansion device1.

In the caulking, drilling, and pressing, the output attachment300described with reference toFIGS. 7A to 8Bis used. The tools attached to the front end of the output rod72and the output receiving portion304are replaced to be used by caulking tools72A and308A, drilling tools72B and308B, and press tools72C and308C according to working contents.

FIGS. 9A to 9Care sectional views for explaining the operation of the caulking process.

In the caulking process, as illustrated on the left side ofFIG. 9A, a first workpiece WA1and a second workpiece WA2that are caulking objects provided with the through-holes are overlapped, and caulking WA3is inserted into the through-holes as indicated by an arrow to prepare the workpiece WA. The workpiece WA is moved between the caulking tools72A and308A.

As described in the sixth usage example, the thrust expansion device1is attached to the articulated robot arm200via the robot adaptor201, and the caulking tools27A and308A may be disposed at the position of the workpiece WA by the movement of the articulated robot arm200. The same applies to drilling and pressing described later.

Thereafter, as illustrated inFIG. 9B, the air cylinder100(not illustrated) attached to the thrust expansion device1on the input side is driven as described inFIGS. 3A and 3C, the output rod72is forwarded in the direction of the workpiece WA, and the amplified pressing force Q1is applied to the abutted workpiece WA to perform the caulking process of the workpiece WA.

After the caulking process is completed, the thrust expansion device1is returned to the initial state by operating the air cylinder100, the workpiece WA is taken out as illustrated inFIG. 9C, and the process is finished.

FIGS. 9D to 9Fare explanatory views of an operation of the drilling process.

As illustrated inFIG. 9D, a projecting portion is formed on the drilling tool72B and a recessed portion is formed on a drilling tool308B according to a size and a shape of a hole to be opened.

A workpiece presser72X is disposed so that a workpiece WB does not shift when drilling. The workpiece presser72X is formed in a bottomed cylindrical shape in which a through-hole through which a projecting portion of the drilling tool72B passes is formed at a center.

Since the workpiece presser72X is formed to have a small diameter of an outer circumferential surface, a coil spring72Z is inserted to bias the workpiece presser72X in the output direction against the output rod72. Therefore, as illustrated inFIG. 9D. In a state before the workpiece presser72X abuts against the workpiece WB, a front end surface of the projecting portion formed on the drilling tool72B is positioned inside the outer surface (front end surface) of the workpiece presser72X.

A through-groove is formed in a body portion of the workpiece presser72X in the axial direction, and the workpiece presser72X biased by a coil spring72Z is prevented from coming out of the output rod72by a stopper72Y press-fitted into the output rod72.

When performing the drilling process, as illustrated by an arrow inFIG. 9D, the prepared workpiece WB is moved between the drilling tools72B and308B.

Thereafter, as illustrated inFIG. 9E, the air cylinder100(not illustrated) attached to the thrust expansion device1is driven, and the output rod72is forwarded in the direction of the workpiece WB. The workpiece presser72X abuts against the output rod72while the output rod72forwards, and the workpiece WB is pressed by the workpiece presser72X by a biasing force of the coil spring72Z as the output rod72forwards.

As the output rod72further forwards, the front end of the drilling tool72B abuts against the workpiece WB and further penetrates, so that a desired hole is formed in the workpiece WB.

After finishing the drilling process, the thrust expansion device1is returned to the initial state by operating the air cylinder100(workpiece presser72X is also returned to the original position by the biasing force of the coil spring), and the workpiece WB is taking out and the process is finished as illustrated inFIG. 9F.

As described above, by changing the output attachment300in various ways, various processes using the common thrust expansion device1can be performed.

FIGS. 9G to 9Iare explanatory views of operations of a press working.

As illustrated inFIG. 9G, a projecting portion is formed on the press tool72C and a recessed portion is formed on the press tool308C in accordance with a shape formed by the press working.

At the time of the press working, as illustrated by an arrow, a prepared workpiece WC is moved between the press tools72C and308C.

Thereafter, as illustrated inFIG. 9H, the air cylinder100(not illustrated) attached to the input side of the thrust expansion device1is driven to forward the output rod72in the direction of the workpiece WC and applies the amplified pressing force Q1to the abutted workpiece WC. Therefore, the press working of the workpiece WC is performed.

After the press working is finished, the thrust expansion device1is returned to the initial state by operating the air cylinder100, and the workpiece WC is taken out and the process is finished as illustrated inFIG. 9I.

Next, a seventh usage example of the thrust expansion device1will be described.

In the sixth usage example, the case in which the output attachment300is attached to the thrust expansion device1and the thrust expansion device1is attached to the articulated robot arm200via the robot adaptor201is described. In the sixth usage example, it is necessary to separately perform the operation of attaching the thrust expansion device1to the articulated robot arm200and the operation of attaching the output attachment300to the thrust expansion device1.

Therefore, in the seventh usage example, an output attachment350having both the function of the robot adaptor201and the function of the output attachment300is used.

FIG. 10is an explanatory view of the seventh usage example of the thrust expansion device1.

InFIG. 10, the same portions as those of the output attachment300and the robot adaptor201in the sixth usage example are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

As illustrated inFIG. 10, the output attachment350includes an arm portion303, and the same output receiving portion304as that of the sixth usage example is integrally formed at one end portion.

The other end side of the arm portion303is not the attachment base portion302but is integrally provided with a robot adaptor351having the same shape as that of the sixth usage example.

The robot adaptor351and the arm portion303are the same as the robot adaptor201and the arm portion303of the sixth usage example except that the robot adaptor351and the arm portion303are formed to be slightly longer than that in the sixth usage example in the axial direction in order to integrally form both.

The tools (caulking tools72A and308A, drilling tools72B and308B, and press tools72C and308C) attached to the output receiving portion304and the output rod72are the same as those in the sixth usage example.

In the seventh usage example, when the thrust expansion device1is attached to the articulated robot arm200, the following procedure is used.

First, the robot adaptor351of the output attachment350is attached to the front end of the articulated robot arm200using a positioning pin202and is fixed by four bolts204.

Next, the thrust expansion device1is fixed to the robot adaptor351of the output attachment350by four pressing bolts206using the input-side lid3and the output-side lid5.

Thus, in the seventh usage example, since the robot adaptor351is integrally formed as a part of the output attachment350, the operation is completed only by attaching the output attachment350to the articulated robot arm200.

As described above, the output attachment of the present invention is configured such that working jigs such as the caulking tool308A, the drilling tool308B, and the press tool308C can be replaced according to the workpiece shape to be processed and various working steps. Therefore, it is easy to handle various processes.

Next, an eighth usage example will be described.

In the eighth usage example, the air cylinder100is attached to the thrust expansion device1on the input side, and a chuck device440is attached to the thrust expansion device1on the output side (output lid5) by a diaphragm.

FIGS. 11A to 11Dare explanatory views of the eighth usage example in which the chuck device440is attached to the thrust expansion device1.FIG. 11Aillustrates a state in which the chuck device440is opened by the thrust expansion device1, andFIG. 11Billustrates a closed state thereof. InFIGS. 11A and 11B, the output side of the thrust expansion device1from a wavy line is illustrated in cross section in order to make it easy to understand a state inside the thrust expansion device1.

FIG. 11Cis a view of the chuck device440of the eighth usage example as viewed from the output side, and a cross section taken along line C-C illustrated inFIG. 11Cis illustrated inFIGS. 11A and 11B.

FIG. 11Dis an exploded view of the chuck device of the eighth usage example.

As illustrated inFIGS. 11A to 11D, the air cylinder100described in the other usage examples is attached to the thrust expansion device1on the input side, but an electric cylinder130or the like can also be attached.

On the other hand, the chuck device440is attached to the thrust expansion device1on the output side via a chuck attachment400.

The chuck attachment400is provided with bolt holes at six locations on an outer circumference thereof, and is fixed to the output-side lid5of the thrust expansion device1by bolts401. The chuck attachment400is an example of the output attachment.

As illustrated inFIG. 11D, the chuck attachment400is provided with a through-hole at a center portion. The through-hole has a small inner diameter portion400aof which an inner diameter is slightly larger than an outer diameter of the output rod72, a lame inner diameter portion400cof which the output side is the same size as an outer diameter of a diaphragm portion451, and a medium inner diameter portion400bhaving an inner diameter of a size between the small inner diameter portion400aand the large inner diameter portion400c.

A stopper402for restricting a movement distance of the output rod72is fixed by a bolt403on a bottom surface (stepped portion with the small inner diameter portion400a) of the medium inner diameter portion400bof the chuck attachment400. The diaphragm portion451is disposed in the large inner diameter portion400cand is fixed to the chuck attachment400by a bolt454.

The diaphragm portion451includes a thin plate diaphragm that can be elastically deformed in a thickness direction, and a thick portion formed on an outer circumference of the diaphragm. The diaphragm portion451is fixed to the chuck attachment400by the bolt403at the thick portion, together with a claw452described later.

On the other hand, the output rod72and an opening/closing rod72E screwed to the front end of the output rod72are inserted into the small inner diameter portion400aof the chuck attachment400. The output rod72is provided with a screw portion72E1on the front end side where male screws are engraved, a small diameter portion72E2having a larger outer diameter than the screw portion72E1, and a flange portion72E3having a larger outer diameter than the small diameter portion72E2. A stopper402is inserted into the small diameter portion72E2.

A through-hole having an inner diameter larger than the outer diameter of the small diameter portion72E2of the opening/closing rod72E and smaller than the outer diameter of the flange portion72E3is formed at a center of the stopper402.

A chuck mechanism portion450includes the diaphragm portion451having a diaphragm which is elastically deformable in the thickness direction, and a thick portion on the outer circumference, and six claws452fixed radially on a surface of the diaphragm portion451at equal intervals in the circumferential direction. The claw452is fixed by a bolt453to the thick portion of the diaphragm portion451.

The diaphragm of the diaphragm portion451is formed in a substantial disc shape and has a central hole penetrating at the center.

As described above, the diaphragm portion451is fixed to the chuck attachment400by the bolt454at the thick portion on the outer circumference. Therefore, the diaphragm formed in a thin portion of the diaphragm portion451is formed to open the chuck by being elastically deformed by pressing the vicinity of the center hole in the thickness direction in accordance with the movement, in the output direction, of the opening/closing rod72E fixed to the front end of the output rod72. When closing the chuck, the output rod72retreats, and the pressing force to the diaphragm is removed, so that the elastic deformation of the diaphragm returns to the original state and the chuck is closed.

The claw452fixed to the diaphragm portion451can be moved by the elastic deformation in opening and closing directions with respect to the central axis.

FIG. 11Aillustrates a state in which the claw452is opened by pressing the diaphragm so that the workpiece900to be chucked can be inserted, andFIG. 11Billustrates a state in which the workpiece900inserted by closing the claw452by pulling back the diaphragm is chucked.

That is, as described inFIGS. 3A to 3D, the input rod101that has driven the air cylinder100is forwarded into the hydraulic chamber8. Therefore, a pressure in the hydraulic chamber8is amplified, the piston portion71(seeFIGS. 3A to 3D) and the output rod72also forward, and the amplified thrust from the opening/closing rod72E at the front end of the output rod72is applied in the direction of pressing the diaphragm. As a result, the claw452is opened.

On the other hand, by inserting the workpiece900between the claws452and returning the input rod101of the air cylinder100to the input side, the pressure in the hydraulic chamber8also decreases, and the opening/closing rod72E is also pulled back to the input side. The elastic deformation of the diaphragm returns to the original state and the workpiece900is chucked.

In general, the diaphragm chuck device is difficult to open because the pressing force required to open the chuck increases as the outer diameter decreases. The drive cylinder that is opened and closed by attaching the small chuck device is also small, and the thrust is insufficient, making it more difficult to open.

On the other hand, according to the thrust expansion device1of the present embodiment and the eighth usage example, the thrust capable of outputting from the output rod72is large even when the small chuck device440(about 2 inches in outer diameter) is used. Therefore, the opening amount is extremely large at ϕ0.8 mm, and a gripping force of the chuck can output 1.4 kN.

The chuck attachment400has a configuration in which the diaphragm portion451serving as gripping means for gripping the workpiece can be replaced in accordance with the workpiece shape, so that it can easily cope with workpieces of different sizes.

Next, a thrust expansion device according to a second embodiment will be described.

In the thrust expansion device1(hereinafter referred to as the first embodiment) described with reference toFIGS. 1A to 10, a case is described in which the air cylinder100or the like is attached, so that the axis of the input rod101of the air cylinder100attached to the input side coincides with the axis of the piston portion71and the output rod72.

However, in the thrust expansion device1of the first embodiment, the entire device becomes longer in the axial direction in the connected state of the air cylinder100.

Therefore, in thrust expansion devices1band1cof the second and third embodiments, the air cylinder100or the like is attached to the thrust expansion devices1band1c, so that the axis of the input rod101disposed on the input side is orthogonal to the axis of the piston portion71and the output rod72. In the embodiment, a case in which both axes are orthogonal is described, but each portion can also be disposed so as to be attached in a diagonal direction (inclination direction).

FIG. 12illustrates a cross section of the thrust expansion device1bof the second embodiment. In the thrust expansion device1bofFIG. 12, a case in which the air cylinder100is connected to the input side is illustrated as in the first usage example (FIGS. 3A to 3C) in the first embodiment.

The same portions as those of the thrust expansion device1in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted as appropriate. The description will focus on the different portions.

As illustrated inFIG. 12, a cylinder2bof the thrust expansion device1bis formed in a rectangular parallelepiped shape, and includes a cylindrical cylinder recessed portion2b1formed on one end surface, a cylindrical input recessed portion2b3formed on an end surface orthogonal to an end surface on which the cylinder recessed portion2b1is formed, and a communication portion2b2connecting the cylinder recessed portion2b1and the input recessed portion2b3.

In the cylinder recessed portion2b1, members on the output side from the input-side lid3and the lid adaptor4in the second embodiment, that is, the piston portion71, the output rod72, the output-side lid5, the stop lid6, the guide pin77, the rotation preventing pin75, and the like are disposed in the same manner as those in the first embodiment. The piston portion71provided in the inner circumferential surface of the cylinder recessed portion2b1and the cavity portion73of the output rod72form a hydraulic chamber8a.

Similar to the first embodiment, an output-side lid5and the stop lid6are disposed on an open end of the cylinder recessed portion2b1.

On the other hand, the same input-side lid3as that of the first embodiment is fixed to the open end of the input recessed portion2b3by a pressing bolt33, and the lid adaptor4is fixed to the input-side lid3by a pressing bolt44.

The air cylinder100is fixed to the lid adaptor4by a pressing bolt109. A length (depth of the recessed portion) of the input recessed portion2b3is formed deeper than a maximum operating range of the input rod101of the connected air cylinder100.

The input recessed portion2b3forms a hydraulic chamber8c.

The communication portion2b2forms a hydraulic chamber8bby connecting the cylinder recessed portion2b1and the input recessed portion2b3.

The cylinder2bis provided with an oil filler connected to the communication portion2b2to supply the oil, and is closed by the oil filler plug22after supplying oil into the hydraulic chambers8ato8c.

The oil fillers to the hydraulic chambers8ato8cmay be formed at other positions connected to the communication portion2b2, and may be formed at positions connected to the cylinder recessed portion2b1and the input recessed portion2b3.

The operation when driving the thrust expansion device1bof the second embodiment illustrated inFIG. 12is the same as that of the first usage example (FIGS. 3A to 3C) of the first embodiment in which the same air cylinder is connected to the input side.

When air is supplied from the inlet/outlet hole102in a state in which the inlet/outlet hole103of the air cylinder100is open, the input rod101enters the hydraulic chamber8c.

When the input rod101enters the hydraulic chamber8cand presses the oil in the entire hydraulic chambers (8ato8c), the piston portion71and the output rod72move in the output direction (downward in the drawing) by the hydraulic stroke OS (seeFIGS. 3A and 3C). The thrust amplified by the hydraulic pressure is output from the front end of the output rod72.

A case, in which the thrust expansion device1bis returned from the state in which the expanded thrust is output to the initial state, is the same as that of the first usage example of the first embodiment.

Next, the thrust expansion device1caccording to a third embodiment will be described.

FIG. 13illustrates a cross section of the thrust expansion device1cof the third embodiment. In the thrust expansion device1cofFIG. 13, similarly to the third usage example (FIGS. 4A and 4B) in the first embodiment, a case in which the electric cylinder130is connected to the input side is illustrated.

The same portions as those of the thrust expansion device1in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted as appropriate. The description will focus on the different portions.

The thrust expansion device1baccording to the second embodiment described with reference toFIG. 12is configured, such that the small diameter of the communication portion2b2is formed, and the axis of the input rod101of the air cylinder100to be connected is disposed on the output side of the output rod72from the axis of the communication portion2h2. Therefore, in the thrust expansion device1bof the second embodiment, the entire height (length of the output rod72in the output direction) of the thrust expansion device1bis made smaller.

On the other hand, in the thrust expansion device1cof the third embodiment, as illustrated inFIG. 13, the axis of the communication portion2b2and the axis of the input rod of the cylinder to be connected are made to coincide with each other. The inner diameter of the communication portion2b2is formed in a size such that the input rod of the cylinder connected to the input side can enter the inner diameter.

According to the thrust expansion device1cof the third embodiment, the communication portion2b2can be used as in the movable range of the input rod. Therefore, an entire length of the thrust expansion device1cin a lateral direction (direction which is orthogonal to the output direction of the output rod72and in which the input-side lid3is disposed) can be shortened compared to the thrust expansion device1bof the second embodiment.

As illustrated inFIG. 13, in the thrust expansion device1c, the communication portion2b2serving as the hydraulic chamber8bis formed in the rectangular parallelepiped cylinder2c, with an inner diameter into which the input rod131of the electric cylinder130can be inserted, that is, an inner diameter which is slightly larger than the diameter of the input rod131.

The input recessed portion2b3is formed at a position at which the center of the input-side lid3and the lid adaptor4on a side on which the electric cylinder130is disposed coincides with the axis of the communication portion2b2.

In the present embodiment, as illustrated inFIG. 13, the hydraulic chamber8cis formed in the input recessed portion2b3. However, since the movable range of the input rod131exists in the communication portion2b2, the hydraulic chamber8cmay be eliminated. In this case, the input-side lid3in a state of abutting against the bottom surface of the input recessed portion2b3is fixed to the cylinder2cby the pressing bolt33.

The operation of driving the thrust expansion device is in the third embodiment configured as described above is the same as that of the thrust expansion device1bof the second embodiment.

As in the first embodiment, by using various adaptors, the first to eighth usage examples can be applied to the thrust expansion devices1band1cof the second and third embodiments.

Moreover, in the thrust expansion devices1band1cillustrated inFIGS. 12 and 13, the cavity portion73is formed in the piston portion71and the output rod72. However, unlike the thrust expansion device1of the first embodiment, since the input rod101of the air cylinder100or the like does not enter the cavity portion73, the cavity portion73may not be formed.

In the second embodiment, the air cylinder (FIG. 12) and in the third embodiment, the electric cylinder (FIG. 13) are respectively used as the input-side actuators. However, the input-side actuator may be replaced with respect to each of the thrust expansion devices1band1c.

In the thrust expansion devices1band1cof the second and third embodiments described above, the disposition surfaces of the input-side lid3and the output-side lid5are orthogonal to the rectangular parallelepiped cylinders2band2c. In the first embodiment, since the disposition surfaces of the input-side lid3and the output-side lid5are in parallel to each other, the side surfaces of the input-side lid3to which the robot adaptor201is assembled and the output-side lid5are also parallel to each other, but are orthogonal to each other in the second and third embodiments. When the robot adaptor201is assembled in the second and third embodiments, bolt holes may be disposed in accordance with the positions of the side surfaces of the input-side lid3and the output-side lid5orthogonal to each other, and may be fixed by the pressing bolts206. Moreover, as long as an assembly strength of the robot adaptor201can be sufficiently secured, the robot adaptor201may be assembled to only one of the input-side lid3and the output-side lid5in the first to third embodiments. Further, in the thrust expansion devices1,1b, and1cof the first to third embodiments, the robot adaptor201can be directly fixed to the cylinders2,2b, and2c.

That is, fixing means for fixing the input actuator (air cylinder100, electric cylinder130, or the like), output fixing means for fixing the output attachment (output attachment300, chuck attachment400, or the like), and robot fixing means for fixing the robot adaptor201for attaching the articulated robot arm200can be disposed in at least one of the cylinder, the output-side lid portion, and the input-side lid portion.

As described above, according to the thrust expansion device1of the present embodiment, since it is separated and independent from the input-side actuator, a wide variety of actuators can be easily attached and replaced, and there is no need to have dedicated or integral actuator. Various inexpensive commercially available actuators can be easily attached and replaced.

It is possible to easily expand the thrust of various actuators by attaching various actuators having not only the air cylinder but also the electric type cylinder and other driving sources to the thrust expansion device1.

Various sizes and outputs of the input-side actuator can be easily changed later, a final performance of the output rod can be easily changed, and convenience can be improved.

Further, according to the thrust expansion devices1band1cin the second and third embodiments, the cylinder attaching adaptor (lid adaptor4or the like) is disposed so as to be in an angular direction in which the axis of the input rod in various cylinders connected to the input side is inclined with respect to the axis of the output rod72, preferably in the right angle direction. The hydraulic chamber8athat applies the hydraulic pressure to the piston portion71and the output rod72, and the hydraulic chamber8cthat receives the pressure from the input rod of the cylinder on the input side are in communication with each other through the hydraulic chamber8b.

Therefore, the length of the output rod72of the thrust expansion devices1band1cin the output direction can be reduced. Therefore, it is possible to improve the operability when the thrust expansion devices1band1creduced in size are attached to the articulated robot arm200via the robot adaptor201described in the sixth to eighth usage examples.