TOOL GRINDING MACHINE

A tool grinding machine comprises a casing formed with at least one air inlet and at least one first air outlet; a driving component disposed in the casing; and a diversion structure. The driving component comprises a motor with a motor housing; and an airflow generator rotating synchronously with the motor and located at an end of the motor that is not connected to a grinding member. The motor housing comprises at least one first opening and at least one second opening communicating with an interior of the motor. The diversion structure is disposed in the casing or on the motor housing, and the diversion structure is provided to enable the tool grinding machine to define a first airflow path, which is composed of the air inlet, the first opening, the interior of the motor, the second opening, the airflow generator and the first air outlet sequentially.

FIELD OF THE INVENTION

The invention relates to a tool grinding machine, and more particularly to a tool grinding machine capable of enabling a heat-dissipating airflow to enter an interior of a motor and providing heat dissipation to a part of a casing for gripping.

BACKGROUND OF THE INVENTION

Although most of the existing tool grinding machines are equipped with an airflow generator linked with the motor to dissipate the heat of the tool grinding machine in operation through the airflow generator. As disclosed in CN 101636245B, in the design of the tool grinding machine, the airflow generator is disposed between the motor and the grinding member, and therefore the main object of the airflow generator is not to dissipate heat, but to discharge dust, heat dissipation is just an additional effect. When the airflow generator acts, the opening provided at the handle will be used as an air inlet to generate wind current in the casing of the tool grinding machine. The wind current passes through the outside of the motor, and is finally discharged at the part of the casing facing toward the grinding member. The wind current path designed in such a way is too long, and the effect of dissipating heat is limited. Furthermore, in order to enhance the user's experience of gripping, the existing tool grinding machines are designed with a structure that is easy to grip, which makes the problem of heat dissipation in the casing of the tool grinding machine more obvious.

If the tool grinding machine is implemented by adopting the aforementioned configuration of the airflow generator, the temperature inside the casing will rise significantly due to the heat generated during the operation of the motor, and the temperature of the casing surface will also rise significantly with the rise in temperature inside the casing, and the user's palm will feel the significantly increased temperature of the casing surface, which is detrimental to the experience for use.

In order to solve the aforementioned problem that heat dissipation inside the tool grinding machine is not easy, U.S. Pat. No. 7,270,598 discloses a technical solution for the tool grinding machine, external air is introduced into the interior of the tool grinding machine to dissipate heat. In the patent, when the dusty gas generated by grinding is sucked by the dust suction pipe, the gas pressure inside the tool grinding machine changes, so that the external air can enter the interior of the tool grinding machine through the air inlet and then enter the dust suction pipe, and the external air travels through the motor and dissipates heat from the motor as it flows in the direction of the dust suction pipe. However, the structure disclosed in U.S. Pat. No. 7,270,598 cannot be applied to tool grinding machines implemented by gripping, because the position of the air inlet is at the top of the casing, if such a design is adopted, the user will block the air inlet while gripping the tool grinding machine, causing poor air intake effect of the air inlet, and the heat dissipation effect on the motor is reduced.

In addition, although technical solutions that can reduce the temperature in the casing are disclosed in the TW 1751912 that belongs to the applicant of the present invention, with the wind current inlet disposing at the body of the casing, the wind current outlet disposing at the head of the casing, and the airflow generator disposing near the wind current outlet, such dispositions will have the problem of causing the wind current path to be too long, resulting in limited heat dissipation effect. In addition, the patent TWI751912 did not provide a technical solution to dissipate heat inside the motor, thus the problem of waste heat accumulation inside the motor is still obvious.

SUMMARY OF THE INVENTION

A main object of the invention is to solve the problem that the conventional hand-held tool grinding machine does not have an ability to dissipate heat inside a motor, resulting in a significant temperature rise of a casing.

A secondary object of the invention is to solve the problem that temperature rise of a casing is still obvious due to a heat dissipation wind current path of the conventional hand-held tool grinding machine being too long.

In order to achieve the above objectives, the invention provides a tool grinding machine comprising a casing, a driving component, and a diversion structure. The casing is provided for operating the tool grinding machine in a gripping manner, and the casing is formed with at least one air inlet and at least one first air outlet. The driving component is installed in the casing, and the driving component comprises a motor and an airflow generator that rotating synchronously with the motor, wherein the motor comprises a stator, a rotor, an output shaft assembled with the rotor, and a motor housing disposed around the stator and the rotor, and wherein the output shaft comprises a first end facing the casing and assembled with the airflow generator, and a second end opposite from the casing and assembled with a grinding member, and wherein the motor housing comprises at least one first opening generating a ventilation relationship with the at least one air inlet, and at least one second opening communicating with an interior of the motor and facing the airflow generator. The diversion structure is disposed at one of two positions including inside the casing and on the motor housing, the diversion structure is provided to enables the tool grinding machine to define a first airflow path which is composed of the at least one air inlet, the first opening, the interior of the motor, the second opening, the airflow generator and the at least one first air outlet in sequence.

In one embodiment, the diversion structure is disposed in the casing and is interposed between the at least one first air outlet and the at least one air inlet.

In one embodiment, the diversion structure is a baffle formed on the motor housing and contacting an inner wall of the casing after the motor housing is assembled.

In one embodiment, an interior of the casing is divided into a motor space and a grinding space separated from the motor space, and the first airflow path only performs in the motor space.

In one embodiment, the casing is divided into a head for gripping and a body, the casing is composed of at least two shells, and the motor housing is connected to one of the at least two shells.

In one embodiment, the motor housing comprises a protruding rib formed on a bottom edge of the motor housing and in contact with an inner wall of the casing, and the protruding rib divides the interior of the casing into the motor space and the grinding space.

In one embodiment, the motor comprises an end plate mounted on an end of the motor housing without forming the second opening, and the end plate provides the stator to be fixed thereon.

In one embodiment, the casing is divided into a head for gripping and a body, the casing comprises a manipulation pressing plate assembled on the body, and at least one second air outlet, the tool grinding machine comprises a deflector disposed in the casing and located at a junction of the head and the body, the deflector is provided to enable the tool grinding machine to define a second airflow path which is composed of the at least one air inlet, the first opening, the interior of the motor, the second opening, the airflow generator and the at least one second air outlet in sequence.

In one embodiment, the deflector comprises an air guiding part facing the body, and the air guiding part comprises a main guide surface and two auxiliary guide surfaces respectively connected to two sides of the main guide surface.

In one embodiment, the auxiliary guide surface is composed of a plurality of arcuate surfaces.

In one embodiment, the deflector is in an arcuate shape, and the deflector comprises two flow stop blocks respectively disposed at two ends of the deflector.

In one embodiment, a level height of the at least one first air outlet on the casing is higher than a level height of the at least one air inlet on the casing.

In one embodiment, the casing comprises at least one dust filter disposed at the air inlet.

In one embodiment, the airflow generator is a centrifugal fan.

Accordingly, compared with the prior art, the invention has the following features that the first airflow path is generated inside the tool grinding machine through the diversion structure, the air inlet and the first air outlet on the casing, and the first opening and the second opening on the motor housing, so that the problem of severe temperature rise in the motor and on the casing surface can be specifically solved since the first airflow path flowing through the interior of the motor, thereby avoiding a user's palm to feel obvious temperature rise. In addition, the first airflow path of the invention is shorter than that of the prior art, thus capable of further enhancing a heat dissipation effect.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The detailed description and technical content of the invention are described below with reference to the accompanying drawings.

Please refer toFIG.1,FIG.2,FIG.3,FIG.4,FIG.5andFIG.6, the invention provides a tool grinding machine20, the tool grinding machine20comprises a casing21, a driving component22, and a diversion structure24. Wherein the casing21is provided for a user to operate in a gripping manner, a position where the user grips the casing21is just above the driving component22. More specifically, the user's palm is located at a position above the driving component22. The casing21is formed with at least one air inlet211and at least one first air outlet212, wherein a level height of the first air outlet212on the casing21is higher than a level height of the air inlet211on the casing21, which means that the air inlet211is closer to a working surface of the tool grinding machine20where grinding operation is performed. In order to prevent dust from entering the air inlet211, in one embodiment, the casing21comprises at least one dust filter disposed at the air inlet211, and the dust filter can be a filter screen or a filter cotton that does not excessively affect airflow. Furthermore, the first air outlet212is not disposed on a top of the casing21, that is, exhaustion of the first air outlet212is not affected when the user gripping the casing21.

In addition, the driving component22is installed in the casing21, and the driving component22comprises a motor221, and an airflow generator222that rotates synchronously with the motor221. The motor221comprises a stator223, a rotor224, an output shaft225assembled with the rotor224, and a motor housing226disposed around the stator223and the rotor224. The output shaft225has a first end227and a second end228opposite to the first end227. Directions shown in the tool grinding machine20inFIG.6are taken as an example, the first end227is a top end of the output shaft225, the second end228is a bottom end of the output shaft225, the first end227faces an interior of the casing21and is assembled with the airflow generator222, and the second end228is assembled with a grinding member25. It can be known from the foregoing that if the grinding member25is located below the motor221, the airflow generator222will be located above the motor221. In addition, a level height of the airflow generator222in the casing21can be the same as that of the first air outlet212, or close to the height of the first air outlet212. When the airflow generator222is running, an airflow with an axial direction different from that of the output shaft225is generated. The airflow generator222is a centrifugal fan. The airflow generator222faces the first air outlet212. The airflow generator222comprises a plurality of fan blades236, and a ring plate237provided for the plurality of fan blades236to be disposed thereon. The plurality of fan blades236are arranged to form an impeller, and the airflow generator222emits airflow from between any two of the fan blades236adjacent to each other. Further, distances between the any two of the fan blades236adjacent to each other are not equidistant, but the distances between the two adjacent fan blades236from an inner edge of the ring plate237toward an outer edge of the ring plate237are gradually increased. When the motor221is adopted an external rotor design, the ring plate237can be a part of the rotor224. In addition, in one embodiment, the airflow generator222comprises a connecting ring238, the connecting ring238and the ring plate237are separately disposed at two ends of the plurality of fan blades236respectively. A size of the connecting ring238is not limited to be equal to that of the ring plate237. In addition, the motor housing226comprises at least one first opening229and at least one second opening230, the first opening229is located at a side of the motor housing226, the first opening229and the air inlet211form a ventilation relationship. Further, in one embodiment, the first opening229directly faces the air inlet211. In addition, the second opening230communicates with an interior of the motor221and faces the airflow generator222. Taking the directions of the tool grinding machine20as shown inFIG.2,FIG.3,FIG.4,FIG.5andFIG.6as an example, the second opening230is located at a top of the motor housing226. Furthermore, in this embodiment, the motor221is adopted an external rotor design, the rotor224is disposed outside the stator223, and at least one through-hole234is formed on a side of the rotor224facing the airflow generator222.

The diversion structure24of the invention is disposed inside the casing21or on the motor housing226.FIG.5shows that the diversion structure24is disposed on the motor housing226, andFIG.8shows that the diversion structure24is disposed inside the casing21. Hereinafter, the embodiment shown inFIG.5will be used for explanation, but it is not limited thereto. Please refer toFIG.5andFIG.6, a purpose of the diversion structure24of the invention is to make an airflow entering from the air inlet211and then entering the interior of the motor221through the first opening229only. The diversion structure24enables the tool grinding machine20to define a first airflow path30, and the first airflow path30is composed of the air inlet211, the first opening229, the interior of the motor221, the second opening230, the airflow generator222and the first air outlet212in sequence. Accordingly, when the airflow generator222rotates, an airflow (as shown32inFIG.7) entering from the air inlet211moves along the first airflow path30and dissipates heat inside the motor221along the way, that is, the airflow (as shown32inFIG.7) will dissipate heat from a plurality of coils239disposed on the stator223or the rotor224in the motor221, thereby greatly reducing waste heat accumulated during operation of the motor221, so that a part of the casing21for providing the user gripping will not be significantly heated, and the user's palm will not feel uncomfortable during operation due to obvious temperature rise of the casing21.

Please refer toFIG.5again, when the diversion structure24is installed on the motor housing226, the diversion structure24is a baffle241disposed on the motor housing226, and the baffle241is in contact with an inner wall of the casing21after the motor housing226is assembled to prevent direct communication between the air inlet211and the first air outlet212. In the embodiment shown inFIG.5, the baffle241is formed by extending a top edge of the motor housing226, but the invention is not limited thereto. Please refer toFIG.8. In another embodiment, when the diversion structure24is disposed inside the casing21, the diversion structure24is interposed between the first air outlet212and the air inlet211. Further, the diversion structure24does not necessarily have to be integrally formed by the casing21, but can be an independent component provided in the casing21, such as a soft air choke member242, which is capable of adapting to an inner space of the casing21and generating an air choking effect. Furthermore, inside the casing21can also be equipped with structures for assembling and positioning the diversion structure24, such as protruding block, tenon, and the like.

Please refer toFIG.5andFIG.6again, an interior of the casing21is divided into a motor space213and a grinding space214separated from the motor space213, and the first airflow path30only performs in the motor space213. More specifically, the motor housing226comprises a protruding rib231formed on a bottom edge of the motor housing226to be in contact with an inner wall of the casing21, and the casing21is divided into the motor space213and the grinding space214by the protruding rib231. In one embodiment, the motor221comprises an end plate232mounted on an end of the motor housing226without forming the second opening230, the end plate232not only provides the stator223to be fixed thereon, but also closes an end of the motor housing226that is originally opened, so that an airflow entering from the first opening229can only flow toward a direction of the second opening230. In one embodiment, the motor221comprises an airtight support ring233that is assembled with the motor housing226to support the end plate232, the airtight support ring233and the end plate232cooperate with the protruding rib231in order to divide the interior of the casing21into the motor space213and the grinding space214, and it should be understood that the motor space213and the grinding space214are not communicated with each other in the invention.

Please refer toFIG.4,FIG.5andFIG.6again, based on a shape of the casing21, the casing21is divided into a head215for gripping and a body216. The casing21further comprises a manipulation pressing plate217assembled on the body216, and at least one second air outlet218. On the other hand, the tool grinding machine20comprises a circuit board26and a deflector27, the circuit board26and the deflector27are both disposed in the casing21. The circuit board26is located in the body216and electrically connected to the motor221to control operation of the motor221. The deflector27is disposed at a junction of the head215and the body216. The deflector27enables the tool grinding machine20to define a second airflow path31, and the second airflow path31is composed of the air inlet211, the first opening229, the interior of the motor221, the second opening230, the airflow generator222and the second air outlet218in sequence. It can be known from the foregoing that a starting point of the second airflow path31is also the air inlet211, and also passes through the first opening229, the interior of the motor221, and the airflow generator222to dissipate heat of a part of the casing21where the user gripped, the second airflow path31then enters the body216, so that heat of the circuit board26located in the body216can be dissipated, and finally is discharged from the second air outlet218. Please refer toFIG.9, and in accordance with the above, in one embodiment, the deflector27comprises an air guiding part271, and the air guiding part271guides an airflow moving along the second airflow path31to descend at the air guiding part271, and to move toward the second air outlet218. The air guiding part271comprises a main guide surface272and two auxiliary guide surfaces273respectively connected to two sides of the main guide surface272. Further, the auxiliary guide surface273is composed of a plurality of arcuate surfaces.

Please refer toFIG.3andFIG.9. In one embodiment, the deflector27is disposed close to an edge of the motor housing226and is in an arcuate shape. It should be noted that the deflector27does not cover the first opening229. In addition, the deflector27comprises two flow stop blocks274respectively disposed at two ends of the deflector27. The two flow stop blocks274cooperate with the diversion structure24to limit an airflow entering from the air inlet211to enter the first opening229only. Please refer toFIG.6andFIG.9. In one embodiment, the deflector27is further formed with a wire-passing notch275, and the wire-passing notch275provides a wire235(shown inFIG.3) of the motor221to pass therethrough to connect with the circuit board26.

Please refer toFIG.2, in one embodiment, the casing21is composed of at least two shells219, and the motor housing226is connected to one of the two shells219. Further, in one embodiment, the motor housing226is integrally formed with one of the at least two shells219.