Patent Description:
In a work machine such as a hydraulic excavator, a technology of assisting operator's monitoring of the surroundings of the work machine by displaying an image obtained by a camera provided on a machine body on a monitor in a cab has been known.

As a technology concerning such monitoring of the surroundings of a work machine, for example, Patent Document <NUM> discloses a work vehicle surrounding monitor system in which a monitor region is set in the periphery of a work vehicle and the presence of a worker in the monitor region is detected. The work vehicle surrounding monitor system includes a regressive reflection material worn by the worker, and a surrounding monitor device that applies laser light in a scanning manner from the work vehicle toward the monitor region, receives laser light reflected by the regressive reflection material, and detects the presence of the worker based on a light reception level. The regressive reflection material includes a cube corner reflector in which a multiplicity of cube corner prisms are arranged. The surrounding monitor device includes a coaxial regressive-reflection type photoelectric sensor that applies non-diffused laser light, receives the reflective light substantially coaxially, and outputs a light reception level. A laser light source of the photoelectric sensor is pulse-driven at a predetermined cycle, and the presence of the worker is detected based on the received light pulse.

In addition, Patent Document <NUM> discloses a construction machine object detection system that detects an object present in the surroundings of a construction machine including an upper swing structure mounted on a lower track structure through a swing mechanism. The construction machine object detection system has an object detection section that detects an object based on an output of a scanning type distance measuring device attached to the upper swing structure. Light emitted from the scanning type distance measuring device passes through a gap between the upper swing structure and the lower track structure. Patent Document <NUM> discloses an operation restrictor for a construction machine including human detecting means for detecting a human on the basis of a plurality of predetermined ranges set based on front, rear, left, and right directions of the construction machine and a separate distance from the construction machine, selecting means for selecting contents of restriction for the corresponding one of the predetermined ranges in a case where a human is detected by the human detecting means, and restricting means for restricting an operation of the construction machine based on the restriction contents.

A work machine in accordance with the preamble of claim <NUM> is known from <CIT>.

However, in the prior art described in Patent Document <NUM>, though the worker can be detected by applying laser light in a scanning manner and detecting light reflected from a retroreflective material worn by the worker, other materials and obstacles that do not have a retroreflective material cannot be recognized. In addition, in the prior art described in Patent Document <NUM>, a detection range in a vertical direction is restricted by a plane passing through the gap between the upper swing structure and the lower track structure, so that, although the lower track structure swung relative to the upper swing structure can be excluded from the object of detection, a worker or another obstacle located at a position below a lower surface of the upper swing structure cannot be detected. Therefore, for example, even when the technology of Patent Document <NUM> is applied, the operation of the work machine cannot be suitably restricted when detecting obstacles.

The present invention has been made in consideration of the foregoing. It is an object of the present invention to provide a work machine capable of restraining the contact between the work machine and an obstacle while restraining a reduction in detection range due to exclusion of a structure of the work machine from the object of detection.

The invention is a work machine including a machine body that includes an upper swing structure and a lower track structure, an actuator for driving a machine body, an operation device operated for driving the actuator, a sensor provided on the machine body for detecting objects present in surroundings of the machine body, a restrictor that restricts the driving of the actuator by the operation device, and a controller configured to control the restrictor based on a detection result of the sensor. The sensor is capable of detecting a specific object being a retroreflective material worn by a worker operating in the surroundings of the work machine from among the objects in a distinguishable manner. A detection range of the sensor is defined by a first detection region set so as to at least partially include an operation range of the machine body and a second detection region located adjacent to and above the first detection region. At least a part of a boundary between the first detection region and the second detection region is set so as to be between a lower end of the upper swing structure and an upper end of the lower track structure. The controller is configured to control the restrictor as follows: in a case that an object is detected in the second detection region, restrict the driving of the actuator by the restrictor, in a case that the specific object is detected in the first detection region, restrict the driving of the actuator by the restrictor, and in a case that an object is detected in the first detection region and the object detected in the first detection region is not the specific object, an object is not detected in the second detection region, and the driving of the actuator is not restricted by the restrictor.

According to the present invention, the contact between the work machine and an obstacle can be restrained while restraining a reduction in detection range due to exclusion of a structure of the work machine from the object of detection.

An embodiment of the present invention will be described below referring to <FIG>. Note that, while in the present embodiment a hydraulic excavator is described as an example of a work machine, the present invention is also applicable to other work machines such as a crane and road machines such as a wheel loader.

<FIG> are diagrams schematically depicting an appearance of a hydraulic excavator as an example of the work machine according to the present embodiment, <FIG> being a side view and <FIG> being a top plan view. In addition, <FIG> is a diagram depicting a state in a cab.

In <FIG>, the hydraulic excavator <NUM> generally includes a machine body including a crawler type lower track structure <NUM> and an upper swing structure <NUM> provided swingably relative to the lower track structure <NUM>, and a front work implement <NUM> provided on a front side of the upper swing structure <NUM> in an elevatable manner. Note that a part of the front work implement <NUM> is omitted in <FIG> for simplification of illustration.

The front work implement <NUM> is configured by coupling a plurality of driven members (a boom 3a, an arm 3b, and a bucket 3c) each rotated vertically. A base end of the boom 3a is rotatably supported on a front portion of the upper swing structure <NUM>. In addition, one end of the arm 3b is rotatably coupled to a tip end of the boom 3a, and the bucket 3c is rotatably coupled to the other end (tip end) of the arm 3b. The boom 3a, the arm 3b, and the bucket 3c are respectively driven by a boom cylinder 3d, an arm cylinder 3e, and a bucket cylinder 3f which are hydraulic actuators.

The lower track structure <NUM> includes a pair of crawlers 1e and 1f respectively wrapped around a pair of left and right crawler frames 1c and 1d, and track hydraulic motors 1a and 1b as hydraulic actuators for driving the respective crawlers 1e and 1f through speed reduction mechanisms and the like. Note that, in <FIG>, in regard of each configuration of the lower track structure <NUM>, only one of a pair of left and right configurations is illustrated and denoted by a reference character, while the other configuration is only denoted by a parenthesized reference character and is omitted from illustration.

The upper swing structure <NUM> includes each member disposed on a swing frame serving as a base, and the swing frame is driven to swing relative to the lower track structure <NUM> by a swing hydraulic motor <NUM> which is a hydraulic actuator, whereby the upper swing structure <NUM> can swing relative to the lower track structure <NUM>.

On a front side of the swing frame of the upper swing structure <NUM>, a cab <NUM> on which an operator rides to operate the hydraulic excavator <NUM> is disposed; in addition, an engine <NUM> as a prime mover, a hydraulic pump <NUM> and a pilot pump <NUM> driven by the engine <NUM>, and a hydraulic circuit system for driving hydraulic actuators (the track hydraulic motors 1a and 1b, the swing hydraulic motor <NUM>, the boom cylinder 3d, the arm cylinder 3e, the bucket cylinder 3f) are mounted (see <FIG> described later). Besides, a controller <NUM> configured to control operations of the hydraulic excavator <NUM> as a whole is disposed on the upper swing structure <NUM>.

As illustrated in <FIG>, disposed in the cab <NUM> are a seat 4a on which the operator is seated, operation devices 4b, 4c, 4d, and 4e for performing operations such as a driving operation of the front work implement <NUM>, a swing operation of the upper swing structure <NUM>, and a traveling operation of the lower track structure <NUM>, a gate lock lever 4f, and the like. In addition, in the cab <NUM>, a monitor <NUM> is disposed at such a position as to be easily viewed from the operator seated on the seat 4a and not to hinder the operator from viewing the outside of the cab <NUM>.

A plurality of sensors <NUM> to <NUM> for imaging the surroundings of the upper swing structure <NUM> are mounted on left and right sides and a rear side of an upper portion of the upper swing structure <NUM>. The plurality of sensors <NUM> to <NUM> are respectively referred to as a right side sensor <NUM>, a rear side sensor <NUM>, and a left side sensor <NUM> according to the layout thereof. In other words, the plurality of sensors <NUM> to <NUM> include the left side sensor <NUM> which is provided on a rear side of the cab <NUM> on the left side of the upper swing structure <NUM> and a detection range of which includes the front side and the left side of the upper swing structure <NUM>, the right side sensor <NUM> which is provided on the right side of the upper swing structure <NUM> and a detection range of which includes the front side and the right side of the upper swing structure <NUM>, and the rear side sensor <NUM> which is provided on the rear side of the upper swing structure <NUM> and a detection range of which includes the left and right sides and the rear side of the upper swing structure <NUM>.

<FIG> is a diagram schematically extracting a part of a hydraulic circuit system applied to the hydraulic excavator together with related configurations. Note that, in <FIG>, a configuration of the swing hydraulic motor <NUM> is depicted as a representative of the plurality of hydraulic actuators of the hydraulic excavator <NUM>.

In <FIG>, the hydraulic circuit system includes the engine <NUM> as a prime mover, the hydraulic pump <NUM> and the pilot pump <NUM> driven by the engine <NUM>, the plurality of hydraulic actuators (here, only the swing hydraulic motor <NUM> is illustrated) driven by a hydraulic fluid delivered from the hydraulic pump <NUM>, a plurality of directional control valves (here, only a directional control valve <NUM> for the swing hydraulic motor <NUM> is illustrated) that control flows of hydraulic fluids supplied from the hydraulic pump <NUM> to the plurality of hydraulic actuators, and the plurality of hydraulic pilot type operation devices (here, only the operation device 4b concerning a swing operation is illustrated) that instruct operations of the plurality of hydraulic actuators and generate pilot pressures (operation signals) for changing over the plurality of directional control valves.

The directional control valve <NUM> is of a center bypass type, and has a center bypass passage located on a center bypass line 28a. The center bypass passage is connected in series with the center bypass line 28a, the center bypass passage communicates with the center bypass line 28a when a spool of the directional control valve <NUM> is in a neutral position, and the communication of the center bypass passage with the center bypass line 28a is interrupted when the spool of the directional control valve <NUM> is changed over to a changeover position on the left side or the right side in <FIG>. The upstream side of the center bypass line 28a is connected to a delivery line 26a of the hydraulic pump <NUM>, and a downstream side of the center bypass line 28a is connected to a tank line 29a.

The directional control valve <NUM> can be changed over by a pilot pressure (operation signal) from the operation device 4b. The operation device 4b has a pair of pilot valves that generate a pilot pressure with a delivery pressure of the pilot pump <NUM> as a source pressure, according to an operation amount. For example, when the operation device 4b is operated from the neutral position to a direction corresponding to a left swing (for example, the left side), a pilot pressure generated in one of the pilot valves according to the operation amount is outputted to a pressure receiving section on the right side in <FIG> of the directional control valve <NUM>, whereby the directional control valve <NUM> is changed over to the changeover position on the right side in <FIG>. As a result, the swing hydraulic motor <NUM> is rotated, and the upper swing structure <NUM> is swung in a leftward direction relative to the lower track structure <NUM>. On the other hand, for example, when the operation device 4b is operated from the neutral position to a direction corresponding to a right swing (for example, the right side), a pilot pressure generated in the other pilot valve according to the operation amount is outputted to a pressure receiving section on the left side in <FIG> of the directional control valve <NUM>, whereby the directional control valve <NUM> is changed over to the changeover position on the left side in <FIG>. As a result, the swing hydraulic motor <NUM> is rotated, and the upper swing structure <NUM> is swung in a rightward direction relative to the lower track structure <NUM>.

Solenoid valves 23a and 23b are provided in respective lines from the operation device 4b to the two pressure receiving sections of the directional control valve <NUM>. The solenoid valves 23a and 23b are restrictors that restrict a pilot pressure (operation signal) outputted from the operation device 4b to the directional control valve <NUM>, and restrict the pilot pressure (operation signal) based on a solenoid valve current (command signal) from the controller <NUM> described later, to thereby restrict an operation velocity of the swing hydraulic motor which is a hydraulic actuator.

<FIG> is a diagram depicting a relation between a solenoid valve current outputted from the controller to the solenoid valve and an actuator velocity. The axis of abscissas in <FIG> represents proportions of the solenoid valve currents outputted from the controller <NUM> to the solenoid valves 23a and 23b based on a prescribed value. Here, the value of the solenoid valve current at which the solenoid valves 23a and 23b are fully closed is <NUM>%. In addition, the axis of ordinates in <FIG> represents the velocity of the hydraulic actuator, when the pilot pressure outputted from the operation device 4b to the directional control valve <NUM> is not restricted, as V1. In other words, in <FIG>, when the solenoid valve current is <NUM> (zero) %, the hydraulic actuator is operated at a velocity V1 according to the pilot pressure outputted from the operation device 4b; when the solenoid valve current increases to exceed a certain proportion, the velocity of the hydraulic actuator is restricted attendant on the increase of the solenoid valve current; when the solenoid valve current becomes <NUM>%, the velocity of the hydraulic actuator is restricted to V2 (< V1); and when the solenoid valve current becomes <NUM>%, the velocity of the hydraulic actuator is restricted to <NUM> (zero).

A pilot relief valve (not illustrated) that holds the delivery pressure of the pilot pump <NUM> constant is provided in a delivery line 27a of the pilot pump <NUM>. In addition, a lock valve 27b is provided in the delivery line 27a of the pilot pump <NUM>, and the lock valve 27b can be changed over according to an operation of the gate lock lever 4f. The gate lock lever 4f is provided with a position switch (not illustrated) which is put into a closed state when the gate lock lever 4f is in an unlocked position (lowered position) and which is put into an open state when the gate lock lever 4f is in a locked position (raised position). For example, when the position switch is put into the closed state, a solenoid section of the lock valve 27b is energized through the position switch, and the lock valve 27b is changed over to a communication position. As a result, the delivery line 27a of the pilot pump <NUM> is put into communication, and the delivery pressure of the pilot pump <NUM> is introduced to the operation device 4b and the like. As a result, a pilot pressure is generated by an operation of the operation device 4b or the like, and the hydraulic actuator can be caused to work (operable state). On the other hand, when the position switch is put into the open state, the lock valve 27b is put into an interrupting position. As a result, communication of the delivery line 27a of the pilot pump <NUM> is interrupted. Consequently, a pilot pressure is not generated even if the operation device 4b or the like is operated, and the hydraulic actuator is not caused to work (inoperable state).

Note that a hydraulic circuit system concerning the left and right track hydraulic motors 1a and 1b, the boom cylinder 3d, the arm cylinder 3e, and the bucket cylinder 3f which are not illustrated in <FIG> also has a similar configuration.

In addition, solenoid valves 24a and 24b are provided in respective lines from the operation devices 4d and 4e at least concerning a traveling operation to the two pressure receiving sections of the respective directional control valves (not illustrated) for the hydraulic motors 1a and 1b, and pilot pressures (operation signals) are restricted based on the solenoid valve currents (command signals) from the controller <NUM>, whereby operation velocities of the track hydraulic motors 1a and 1b which are hydraulic actuators are restricted.

The hydraulic excavator <NUM> in the present embodiment configured as above has a surrounding monitor function that restricts operations of the hydraulic excavator <NUM> based on the detection results of the sensors <NUM> to <NUM>.

<FIG> is a functional block diagram schematically extracting a configuration concerning the surrounding monitor function of the hydraulic excavator according to the present embodiment.

In <FIG>, the surrounding monitor function includes the plurality of sensor <NUM> to <NUM>, the solenoid valves 23a, 23b, 24a, and 24b as restrictors, and the controller <NUM> configured to generate command signals to the solenoid valves 23a, 23b, 24a, and 24b based on the detection results of the plurality of sensors <NUM> to <NUM>.

The sensors <NUM> to <NUM> are sensors that detect distances and directions from the sensors <NUM> to <NUM> to an object and output a position of the detected object in a three-dimensional coordinate system as a detection result, and are, for example, infrared depth sensors. In addition, the sensors <NUM> to <NUM> are capable of detecting a retroreflective material and other members (objects) in a distinguishable manner, and output information concerning whether or not the object detected as a detection result is a retroreflective material.

<FIG> is a diagram depicting an example of a detection range of a sensor.

In <FIG>, the detection range of the right side sensor <NUM> of the sensors <NUM> to <NUM> is depicted on a representative basis. As illustrated in <FIG>, a detection range <NUM> of the sensor <NUM> is defined by a first detection region 30b set so as to at least partially include an operation range of the lower track structure <NUM> relative to the upper swing structure <NUM>, and a second detection region 30a set so as to be adjacent to the first detection range 30b, and a boundary between the first detection region 30b and the second detection region 30a is set along a virtual plane perpendicular to a swing shaft of the upper swing structure <NUM> at a height between a lower end of the upper swing structure <NUM> and an upper end of the lower track structure <NUM>. This setting of the detection range is stored in a storage region (not illustrated) of the controller <NUM>, and can be adjusted, for example, through an external apparatus for maintenance or the like.

The first detection region 30b and the second detection region 30a are each determined in terms of an object (member) as the object of detection by the sensor <NUM>. Of a retroreflective material worn by a worker operating in the surroundings of the hydraulic excavator <NUM> and other objects, the first detection region 30b is a detection region whose detection object is only the retroreflective material. In addition, the second detection region 30a is a detection region whose detection object is both the retroreflective material and the other objects. In other words, the controller <NUM> has acquired information concerning the three-dimensional position of the detected object and information concerning the kind of the detected object (whether or not the detected object is the retroreflective material), as a detection result from the sensor <NUM>. In a case where the three-dimensional position where an object is detected is in the first detection region 30b, it is determined that an object is detected only when the detected object is a retroreflective material. Even if an object other than the retroreflective material such as the lower track structure <NUM> is detected, it is determined that the detection of an object is absent. In addition, in a case where the three-dimensional position where an object is detected is in the second detection region 30a, the controller <NUM> determines that an object is detected no matter whether the detected object is a retroreflective material or another object.

The controller <NUM> has an object/retroreflective material determination section 20a and an operation restriction determination section 20b.

<FIG> is a flow chart indicating contents of processing by the object/retroreflective material determination section, and <FIG> is a flow chart indicating contents of processing by the operation restriction determination section.

As depicted in <FIG>, the object/retroreflective material determination section 20a first determines whether or not an object is detected based on detection results from the sensors <NUM> to <NUM> (step S100). Specifically, as described above, it is determined whether a retroreflective material is detected in the first detection region 30b, or whether either object is detected in the second detection region 30a. When the determination result in step S100 is NO, the processing of step S100 is repeated until an object is detected.

In addition, when the determination result in step S100 is YES and the sensor having detected an object is the right side sensor <NUM> or the left side sensor <NUM>, it is determined whether the detected object includes a retroreflective material (step S110), a detection flag A is outputted to the operation restriction determination section 20b when the determination result is YES (step S111), whereas a detection flag B is outputted to the operation restriction determination section 20b when the determination result is NO (step S112), and the processing is finished.

In addition, when the determination result of step S100 is YES and the sensor having detected an object is the rear side sensor <NUM>, it is determined whether or not the detected object includes a retroreflective material (step S120), a detection flag C is outputted to the operation restriction determination section 20b when the determination result is YES (step S121), whereas a detection flag D is outputted to the operation restriction determination section 20b when the determination result is NO (step S122), and the processing is finished.

Subsequently, the operation restriction determination section 20b determines what the detection flag outputted from the object/retroreflective material determination section 20a is (step S200). When the detection flag is determined to be A or C, the solenoid valve currents outputted to the solenoid valves 23a and 23b for swing and the solenoid valve currents outputted to the solenoid valves 24a and 24b for traveling are both made to be <NUM>%, whereby a swing operation and a traveling operation are stopped (step S201), and the processing is finished. In other words, when it is considered that a worker wearing a retroreflective material is detected, both a swing operation and a traveling operation are stopped, whereby contact of the hydraulic excavator <NUM> with the worker can be prevented.

In addition, when it is determined that the detection flag is B in step S200, the solenoid valve currents outputted to the solenoid valves 23a and 23b for swing are set to <NUM>%, whereas the solenoid valve currents outputted to the solenoid valves 24a and 24b for traveling are set to <NUM>%, whereby the operation speed of a swing operation is decelerated and a traveling operation is stopped (step S202), and the processing is finished. In other words, when an object other than a retroreflective material (namely, an object other than a worker) is detected on a lateral side of the hydraulic excavator <NUM> (specifically, a lateral side of the upper swing structure <NUM>), the swing speed is not stopped but is decelerated and the traveling operation is stopped, whereby the contact with the object detected on the lateral side can be suitably restrained while restraining a decrease in operating efficiency.

In addition, when it is detected that the detection flag is D in step S200, the solenoid valve currents outputted to the solenoid valves 23a and 23b for swing are set to <NUM> (zero) % and the solenoid valve currents outputted to the solenoid valves 24a and 24b for traveling are set to <NUM>%, whereby the operation speed of a swing operation is not restricted and a traveling operation is stopped (step S203), and the processing is finished. In other words, when an object other than a retroreflective material (namely, an object other than a worker) is detected on the rear side of the hydraulic excavator <NUM> (specifically, on the rear side of the upper swing structure <NUM>), the swing speed is maintained and a traveling operation is stopped, whereby the contact with the object detected on the rear side can be suitably restrained while restraining a decrease in operating efficiency.

Effects of the present embodiment configured as above will be described.

In a conventional technology of detecting a worker by applying laser light in a scanning manner and detecting light reflected from a retroreflective material worn by the worker, other materials or obstacles not having a retroreflective material cannot be recognized. In addition, in a conventional technology in which the detection range in the vertical direction is restricted by a plane passing between the upper swing structure and the lower track structure, though the lower track structure swung relative to the upper swing structure can be excluded from the object of detection, a worker or other obstacles located at a position lower than the lower surface of the upper swing structure cannot be detected. Therefore, for example, even when the conventional technology of restricting an operation of a work machine in a case where an obstacle is detected is applied, the operation of the work machine cannot be suitably restricted when the obstacle is detected.

On the other hand, the present embodiment provides the hydraulic excavator <NUM> including the operating devices 4b to 4e that output operation signals for driving the track hydraulic motors 1a and 1b, the hydraulic cylinders 3d to 3f, and the swing hydraulic motor <NUM> which are hydraulic actuators, the sensors <NUM> to <NUM> capable of detecting a retroreflective material which is a specific object and other objects in a distinguishable manner, the solenoid valves 23a, 23b, 24a, and 24b as restrictors that restrict driving of the hydraulic actuators by restricting operation signals outputted from the operation devices 4b to 4e, and the controller <NUM> configured to control the solenoid valves 23a, 23b, 24a, and 24b based on detection results of the sensors <NUM> to <NUM>. In the hydraulic excavator <NUM>, the controller <NUM> is configured to control, in a case where an object is detected by the sensors <NUM> to <NUM>, the solenoid valves 23a, 23b, 24a, and 24b based on the information concerning whether or not the object (member) detected by the sensors <NUM> to <NUM> is a retroreflective material and the information concerning whether the position of the object (member) detected by the sensors <NUM> to <NUM> is in the first detection region 30b at least partially including the operation range of the machine body or the second detection region 30a adjacent to the first detection region 30b. Therefore, the contact of the hydraulic excavator <NUM> with an obstacle can be restrained while restraining a reduction in the detection range due to exclusion of the structure of the hydraulic excavator <NUM> from the object of detection.

Claim 1:
A work machine (<NUM>) comprising:
a machine body that includes an upper swing structure (<NUM>) and a lower track structure (<NUM>);
an actuator (1a, 1b, 3d, 3e, 3f, <NUM>) for driving the machine body;
an operation device (4b, 4c, 4d, 4e) operated for driving the actuator;
a sensor (<NUM>, <NUM>, <NUM>) provided on the machine body for detecting objects present in surroundings of the machine body;
a restrictor (23a, 23b, 24a, 24b) that restricts the driving of the actuator by the operation device; and
a controller (<NUM>) configured to control the restrictor based on a detection result of the sensor,
characterized in that
wherein the sensor (<NUM>, <NUM>, <NUM>) is capable of detecting a specific object being retroreflective material worn by a worker operating in the surroundings of the work machine (<NUM>) from among the objects in a distinguishable manner,
a detection range of the sensor is defined by a first detection region (30b) set so as to at least partially include an operation range of the machine body and
a second detection region (30a) located adjacent to and above the first detection region,
at least a part of a boundary between the first detection region and the second detection region is set so as to be between a lower end of the upper swing structure (<NUM>) and an upper end of the lower track structure (<NUM>), and
wherein the controller (<NUM>) is configured to control the restrictor as -follows:
in a case that an object is detected in the second
detection region (30a), restrict the driving of the actuator (1a, 1b, 3d, 3e, 3f, <NUM>) by the restrictor (23a, 23b, 24a, 24b),
in a case that the specific object is detected in the first detection region (30b), restrict the driving of the actuator (1a, 1b, 3d, 3e, 3f, <NUM>) by the restrictor (23a, 23b, 24a, 24b), and
in a case that an object is detected in the first detection region (30b) and the object detected in the first detection region is not the specific object, an object is not detected in the second detection region (30b), the driving of the actuator (1a, 1b, 3d, 3e, 3f, <NUM>) (23a, 23b, 24a, 24b) is not restricted by the restrictor.