JP2003053690A - Hand finger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small hand finger capable of accurately detecting gripping of a workpiece in a short time. SOLUTION: The hand finger has sheet-shaped pressure sensors 3 to 6 which are inserted between a finger part 1 and a hand finger base part 2 having a supporting face S for supporting the finger part 1, and detect pressures which the finger part 1 applies to the supporting face S. Based on the values and distribution of the pressures detected by the pressure sensors 3 to 6, a force applied to the finger part 1 is detected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hand finger for gripping a work by a plurality of fingers.

[0002]

2. Description of the Related Art A conventional hand finger determines whether or not gripping is completed by fixing a proximity sensor or a photoelectric sensor to a finger position at a gripping completion position and obtaining position information from sensor output. , The position information of the hand chuck portion is detected. Further, when a pneumatic device such as an air cylinder is used, according to the prior art, the position at which the gripping is completed is adjusted using a stopper or the like. Furthermore, conventionally, there is a method of detecting a gripping force using a strain gauge.

[0003]

However, in the above-mentioned technique, the so-called safety factor is applied in which the waiting time is set for completion of detection in order to eliminate the influence of the reaction delay of the proximity sensor and to detect the grip reliably. Therefore, the conventional method has a drawback that the tact time at the time of grip detection is increased.

That is, in the conventional method, only the position information is used to determine whether the gripping is completed, and thus the position information alone is not sufficient to compensate for the completion of gripping. This is because grasping may or may not have been completed when the workpiece reaches that position due to variations in the size of the workpiece. If the position information alone is simply used, the work size error cannot be absorbed. Therefore, conventionally, a waiting time for completion of gripping must be provided.

More specifically, when a driving device such as a motor is used as a structure for gripping, a command value for gripping is given as a value smaller than the work size. For example, when the variation in the work size is ± 0.5 mm, a point such as (work size) -0.6 mm is given as the instruction value for gripping the work. However, the size of the work has a variation, and the state where the gripping is actually completed is from the point of (work size) +0.5 mm to (work size) -0.
Possibly exists up to a point of 5 mm.

In order to determine the completion of gripping, a control method is adopted in which the point of reaching the minimum value of the work (work size) -0.5 mm is reached or the determination of completion of grasping is waited until the time to reach the point. . Then, even if the gripping is actually completed at the position of (work size) + 0.5 mm, the weight is put on for the remaining operation time of 1 mm, which causes a problem that the detection of gripping completion is delayed. Will end up.

Further, a sensor such as a proximity sensor or a photoelectric sensor requires a relatively large space when it is attached to a hand portion, and thus there is a concern that the hand size may be increased.

When a pneumatic device such as an air cylinder is used, the position at which the gripping is completed is adjusted by using a stopper or the like. However, in the pneumatic device, the initial movement of the device depends on the state of air in the device. It is not always the same time every time, and it is necessary to insert a wait for the operation start time, and the wait time is often longer than that when driving with a motor.

Further, in the prior art, there is one using a strain gauge for sensing such as gripping force sensing. The method using this strain gauge requires structural analysis of the portion to which the strain gauge is attached. A complicated analysis that is only necessary for the force detection in the 1-axis direction, that is, the gripping force detection is not necessary, but a complicated analysis is necessary for the detection in the 3-axis direction. In particular, the strain gauge has a small size (1 × 1 mm or more), which facilitates downsizing of the hand. However, skill is required to perform structural analysis so that three-axis force detection can be performed efficiently with a small configuration.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a hand finger which is small in size and capable of detecting gripping of a work accurately and in a short time. And Another object of the present invention is to provide a hand finger that can detect a plurality of axial forces with simpler processing.

[0011]

[Means for Solving the Problems] In order to solve the above problems,
In order to achieve the object, a hand finger according to the invention described in claim 1 is a hand finger for gripping a work by a plurality of finger parts, the supporting means having a supporting surface for supporting the finger parts, and the finger. Based on the value and distribution of the pressure detected by the sheet-like pressure detection means, which is inserted between the portion and the support surface, and which detects the pressure applied to the support surface by the finger portion. And an applied force detecting means for detecting the force applied to the finger portion.

According to the first aspect of the invention, the sheet-like pressure detecting means can be inserted between the finger portion and the supporting surface to detect the pressure applied by the finger portion to the supporting surface. . Further, the force applied to the finger portion can be detected based on the value and distribution of the pressure detected by the pressure detecting means.

A hand finger according to a second aspect of the present invention is attached to the finger portion and the supporting means, and the finger portion and the supporting portion are connected by a connecting means having a U-shaped cross section along the attached surface. It is characterized in that it is connected to the means.

According to the second aspect of the present invention, the finger portion and the support means are attached to the finger portion and the support means, and the finger portion and the support means are connected by a connecting means having a U-shaped cross section along the attachment surface. You can

A hand finger according to a third aspect of the present invention is attached to the finger portion and the supporting means, and the finger portion and the supporting portion are connected by a connecting means having a V-shaped cross section along the attached surface. It is characterized in that it is connected to the means.

According to the third aspect of the present invention, the finger portion and the supporting means are attached to the finger portion and the supporting means, and the finger portion and the supporting means are connected by a connecting means having a V-shaped cross section along the attaching surface. You can

The hand finger according to a fourth aspect of the present invention is characterized in that the finger portion and the supporting means are connected by a connecting means provided only on one surface of the finger portion and the supporting means.

According to the invention described in claim 4, the finger portion and the supporting means can be connected by the connecting means provided only on one surface of the finger portion and the supporting means.

The hand finger according to a fifth aspect of the present invention is characterized by further including a pressurizing addition means for applying a pressurizing force to the pressure detecting means.

According to the fifth aspect of the present invention, the pressure can be applied to the pressure detecting means.

The hand finger according to a sixth aspect of the present invention further comprises a pressurizing pressure adjusting means for adjusting the pressurizing pressure applied to the pressure detecting means by the pressurizing applying means.

According to the sixth aspect of the present invention, the pressure applied to the pressure detecting means can be adjusted.

In the hand finger according to a seventh aspect of the present invention, the pressurizing pressure adjusting means automatically sets the pressurizing pressure applied by the pressurizing applying means according to the characteristics of the pressure detecting means. It is characterized in that a pressurizing force set based on the pressure detected by the pressure detecting means is applied to the pressure detecting means.

According to the invention as set forth in claim 7, the pressure to be applied to the pressure detecting means can be automatically set and automatically applied.

A hand finger according to an eighth aspect of the present invention includes a plurality of the pressure detecting means, and the applied force detecting means uses the value and distribution of the pressure detected by each pressure detecting means to apply the finger to the finger portion. It is characterized by comprising a calibration means for detecting the force applied to the plurality of axial directions and calibrating the finger portion in the plurality of axial directions based on the detected forces.

According to the eighth aspect of the present invention, the force applied to the finger portion is detected in a plurality of axial directions by using the value and distribution of the pressure detected by each of the plurality of pressure detecting means. It is possible to calibrate the finger portion in a plurality of axial directions based on the detected force.

The hand finger according to a ninth aspect of the present invention further comprises limiter means for preventing the pressure detecting means from being applied with a pressure of a predetermined value or more.

According to the ninth aspect of the present invention, it is possible to prevent the pressure detecting means from being applied with a pressure of a predetermined value or more.

The hand finger according to a tenth aspect of the present invention is further characterized by further comprising limiter adjusting means for adjusting the pressure limited by the limiter means.

According to the tenth aspect of the invention, it is possible to adjust the value of the pressure that prevents the pressure detecting means from being applied.

In the hand finger according to the invention of claim 11, the limiter adjusting means automatically adjusts the pressure limited by the limiter means based on the pressure detected by the pressure detecting means. Is characterized by.

According to the eleventh aspect of the present invention, it is possible to automatically adjust the value of the pressure that prevents the pressure detecting means from being applied.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION (Embodiment 1) A preferred embodiment of a hand finger according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows the first embodiment.
FIG. 7 is a diagram for explaining a mechanical configuration of gripping a work of the hand finger of FIG. Further, FIG. 2 shows the first embodiment.
FIG. 3 is a block diagram for explaining a configuration for controlling the hand finger of FIG.

The hand finger is provided with a finger portion 1 which is a portion for handling a work when performing automatic assembly or disassembly, and a hand finger base portion 2 having a support surface S for supporting the finger portion 1. The finger part 1 is
It includes a tip portion 1a and a base portion 1b which is a base of the tip portion 1a. Four sheet pressure sensors 3, 4, 5, 6 are fixed on the supporting surface S of the hand finger base portion 2. The base portion 1b of the hand finger has sheet-like pressure sensors 3 to 6
Since the sheet pressure sensors 3 to 6 are located above,
It is in a state of being sandwiched between the finger portion 1 and the hand finger base portion 2.

The sheet-like pressure sensors 3 to 6 are constructed by providing electrodes on both sides of a conductive rubber and measuring the electrical resistance of the conductive rubber which changes according to the applied pressure with the electrodes. . The four sheet-shaped pressure sensors 3 to 6 are arranged in accordance with the four corner portions of the bottom surface of the base 1b.

A plurality of hand fingers shown in FIG. 1 jointly grip a work. When gripping a work, the entire hand fingers are driven in parallel in the ± Y directions to perform gripping operation. After gripping, the finger portion 1 tilts in the Y-axis direction by the gripping force and detects the force from the change in the value of the pressure sensor. Therefore, the movement of each hand finger can be detected by the pressure distribution and the pressure distribution represented by the position of the sheet-shaped pressure sensor that senses the pressure and the magnitude of the detected pressure.

In order to prevent the finger portion 1 from coming off the hand finger base portion 2 when the finger portion 1 is driven, the finger portion 1 and the hand finger base portion 2 are connected by a joint plate. The structure of the joint plate will be described later.

As shown in FIG. 2, the hand finger also includes a control unit 21 having a calculation unit 22 and a memory 24. The control unit 21 uses the sheet-shaped pressure sensors 3-6.
The electric signal indicating the resistance output by is input, and the pressure is calculated by the calculation unit 22 using the value of the electric signal. Then, the hand finger drive unit 23 that drives the hand finger is controlled based on the calculated pressure to drive the hand finger. Further, the memory 24 includes a RAM for storing the value calculated by the arithmetic unit 22 as necessary, a ROM in which a control program is stored, and a memory used as a work memory of the arithmetic unit 22. .

In the above structure, when an external force is applied to the tip portion 1a, the sheet pressure sensors 3 to 6 output a signal according to the external force. The signals output from the sheet pressure sensors 3 to 6 will be described below.

FIG. 3 is a diagram showing a state in which the pressure sheet pressure sensor is taken out from the hand finger of the first embodiment. Each of the four sheet-shaped pressure sensors 3 to 6 is a rectangular sheet, and each corner is arranged so as to match each corner with four corners of the bottom surface (rectangle) of the base 1b. . The sheet pressure sensors 3 to 6 output signals corresponding to the applied pressures.

When handling is performed, the hand finger receives an external force on the front portion of the finger portion 1.
At this time, the sheet-like pressure sensors 3 and 5 output a signal according to the pressure. Further, when a force is applied from the back surface of the hand finger, which is the opposite of the grip, an output is generated in the sheet pressure sensor 4 and the sheet pressure sensor 6.

In order to immediately detect the gripped state, the signals output from the sheet-shaped pressure sensors 3 and 5 are monitored, and when the signal exceeds a preset gripping preset value, "gripping is completed". To detect. Further, the gripping force at this time can be measured by executing a calculation based on the values of the signals output by the sheet-shaped pressure sensors 3 to 6.

When an external force lateral to the gripping direction of the finger portion 1 is generated, the sheet pressure sensor 3,
4 or the sheet pressure sensors 5 and 6 output signals. The direction of gripping a work in the hand finger shown in FIG. 1 is the Y direction in the figure, and the finger part 1 is tilted in the Y-axis direction when gripping the work, and the moment can measure the force from the pressure change of the pressure sensor, that is, the gripping force. .

The inserting direction is the X direction in FIG. 1, and indicates the external force in the X direction with respect to the external force applied to the work when gripping the work and carrying, carrying out, assembling and disassembling operations.
Further, the external force in the lateral direction is the external force in the Z-axis direction in FIG. 1, which is not applied in normal assembly, but is force detection for detecting an unexpected collision or the like.

The formula (1) for obtaining the gripping force Fh will be described below. In the formula (1), S1 is a signal output by the sheet pressure sensor 3, S2 is a signal output by the sheet pressure sensor 4, S3 is a signal output by the sheet pressure sensor 5, and S3 is
Reference numeral 4 is a signal output from the sheet pressure sensor 6. In addition, a in Formula (1) is a constant derived by calibration from a known gripping force. Fh = a {(S1 + S3) / 2- (S2 + S4) / 2} (1)

Further, the insertion force at the time of assembling can be measured by the calculation based on the signals output from the sheet-shaped pressure sensors 3 to 6 similarly to the gripping force. The equation (2) for obtaining the insertion force Fs is described below. In the formula (2), S1 is a signal output from the sheet-shaped pressure sensor 3, and S1 is
2 is a signal output from the sheet pressure sensor 4, S3 is a signal output from the sheet pressure sensor 5, and S4 is a signal output from the sheet pressure sensor 6. Note that b in the formula (2)
Is a constant derived by calibration from a known insertion force. Fs = b {(S1 + S2 + S3 + S4) / 4} (2)

Further, the external force acting in the direction perpendicular to the hand fingers can also be measured by calculation based on the signals output by the sheet-shaped pressure sensors 3 to 6. For example, the vertical force Fv when a force is applied to the finger portion 1 from the direction of the sheet pressure sensor 3 is obtained by the following formula (3).

In the equation (3), S1 is a signal output by the sheet pressure sensor 3, S2 is a signal output by the sheet pressure sensor 4, S3 is a signal output by the sheet pressure sensor 5, and S4 is a sheet pressure. This is the signal output by the sensor 6. In addition, c in Formula (2) is a constant. Fv = c {(S3 + S4) / 2- (S1 + S2) / 2} (3) The vertical force Fv shown in equation (3) is a component force that is orthogonal to the gripping force shown in equation (1).

As described above, the hand finger according to the first embodiment can measure the forces in the three directions by using the sheet-shaped pressure sensors 3 to 6 without performing complicated structural analysis. is there. For this reason, the gripping force, the inserting force, and the vertical force can be obtained in parallel based on the signal measured by one pressure measurement by the sheet pressure sensor. Therefore, it is possible to detect the force acting on the hand finger at a higher speed than in the conventional case, and it is possible to provide a hand finger that can endure high-speed control.

FIG. 4 is a flow chart for explaining the calibration performed by the hand finger of the first embodiment. The automatic calibration is automatically performed by grasping a reference work having an accurate size with the hand fingers.

In the hand finger of the first embodiment, the control unit 21 determines whether or not the model of the hand finger to be used has been changed (step S401). As a result of this determination, if there is no change in the model etc. (step S40)
1: No), and the process ends.

In step S401, if the model of the hand finger is changed (step S401:
Yes), it is determined whether or not the sheet pressure sensors 3 to 6 have been replaced (step S402). As a result of this determination, when the sheet pressure sensors 3 to 6 have not been replaced (step S402: No), the process ends.

If it is determined in step S402 that the sheet pressure sensors 3 to 6 have been replaced (step S402).
402: Yes), the control unit 21 controls the hand finger drive unit 23 to cause the hand fingers to grip the reference work (step S403). And at this time 4
The signals output from each of the sheet pressure sensors 3 to 6 are input, and the constants a, b, and c are calculated by the calculation unit 22 (step S404).

Next, the control section 21 calculates the calculated a, b,
It is determined whether each constant of c is an appropriate value (step S405). This determination is performed, for example, by setting an appropriate value range as a constant in advance and determining whether or not the calculated constant is within the set range.

When it is determined in step S405 that the calculated constant is appropriate, the control unit 21 ends the process. At this time, the calculated constants a, b, and c are
The gripping force, the insertion force, which is stored in the memory 24 and is performed later,
Used to calculate normal force.

Next, the joint plate of the hand finger according to the first embodiment will be described. FIG. 5 is a diagram showing a configuration in which the U-shaped joint plate 51 is provided on the hand finger shown in FIG. The joint plate 51 is attached to the finger portion 1 and the hand finger base portion 2 and has a U-shaped cross section along the attached surface.

In the automatic assembly with the hand fingers, it is particularly important to measure the gripping force and the inserting force. According to the U-shaped joint plate of the first embodiment, it is possible to measure the pressure in two directions, that is, the gripping direction with the hand fingers and the inserting direction of the component gripped with the hand fingers with high sensitivity.

Further, generally, the pressure sensor has a pressure range (a portion having a good linearity) which can be detected with a relatively high sensitivity. Since the pressure applied to the hand finger is measured by using the portion having good linearity, the first embodiment
The sheet pressure sensors 3 to 6 are pre-pressurized to adjust the range of pressures detected.

FIG. 6 shows a state in which a stepped pin 61 is provided on the hand finger shown in FIG. 1 and a pressure is applied to each sheet-shaped pressure sensor, as seen from the direction of arrow A shown in FIG. It is a figure. In the first embodiment, the pressure applied to the sheet-shaped pressure sensor is set to a relatively small value in a portion having good linearity, and it is possible to detect a wide range of pressure with high sensitivity.

Further, if a load higher than the withstand load is applied to the hand fingers, the sheet pressure sensors 3 to 6 may be damaged. In order to prevent breakage of the sheet-shaped pressure sensor, the first embodiment includes a limiter pin 71 that functions as a limiter, as shown in FIG. FIG. 7 is a view showing a state in which the limiter pin 71 is provided at the sheet pressure sensor installation portion of the hand finger shown in FIG. 1 as seen from the direction of arrow A shown in FIG.

The limiter pin 71 is composed of a fixing portion 71b for fixing the limiter pin 71 to the hand finger base portion 2 and a protruding portion 71a protruding on the upper surface of the hand finger base portion 2. The thickness of the protruding portion 71a is a thickness that prevents the upper surface of the hand finger base portion 2 and the bottom surface of the base portion 1b from approaching a distance where the sheet-shaped pressure sensor may be destroyed or plastic deformation occurs. Is set to

(Second Embodiment) Next, a hand finger according to a second embodiment of the present invention will be described. 8 and 9 are diagrams for explaining the mechanical configuration of the hand fingers of the second embodiment for gripping a work. Note that among the configurations shown in FIGS. 8 and 9, the same configurations as those shown in the first embodiment are designated by the same reference numerals, and the description thereof will be partially omitted.

The hand finger of the second embodiment is shown in FIG.
As shown in FIG. 5, the sheet-like pressure sensors 3 to 6 are provided with screw-in type pins 81 for applying pressure. The screw-type pin 81 has a fixing portion 81 for fixing to the base portion 1b.
b, a protruding portion 81b protruding on the upper surface of the base 1b, and a screwed portion 81c. Screw-in pin 8 shown in FIG.
1, the fixing portion 81b is inserted into the insertion hole 82, and the screwing portion 81c is screwed into the hand finger base portion 2 to be fixed.

In the hand finger shown in FIG. 8, the pressure applied to the sheet pressure sensors 3 to 6 by the screw-in type pin 81 can be adjusted by the screwing amount of the screw-in portion 81c. The threaded portion 81c of the threaded pin 81 shown in FIG. 8 is manually screwed by an operator.

In the hand finger of the second embodiment, as shown in FIG. 9, the screw pin 81 can be automatically rotated by using a motor or the like. That is, the hand finger shown in FIG. 9 includes the automatic pressurizing mechanism 91. The pressurizing automatic adjustment mechanism 91 can be rotated with high accuracy by the pressurizing motor (FIG. 10), and the screwing portion 81c can be screwed into the hand finger base portion 2 to an accurate depth.

FIG. 10 is a block diagram for explaining the structure for controlling the hand fingers shown in FIG. The configuration shown in FIG. 10 includes a calculation unit 22 and a control unit 21 having a memory 24, similarly to the configuration shown in FIG. The control unit 21 measures the pressure applied to the hand finger using the signals output from the sheet pressure sensors 3 to 6. Then, the hand finger drive unit 23 and the pressurizing motor 101 are controlled based on the measurement result.

FIG. 11 is a flow chart for explaining automatic adjustment of pressurization performed by the hand finger of the second embodiment. In the hand finger of the second embodiment,
The control unit 21 determines whether the sheet pressure sensors 3 to 6 have been replaced (step S111). If the sheet pressure sensors 3 to 6 have not been replaced (step S111: No), it is determined that the readjustment of the pressurization is not necessary,
The process ends. The reason why the applied pressure is not adjusted when the sheet-shaped pressure sensors 3 to 6 are not replaced is that the range of pressure at which good linearity is obtained is generally different for each sheet-shaped pressure sensor.

When it is determined in step S111 that the sheet pressure sensors 3 to 6 have been replaced (step S11).
111: Yes), the control unit 21 acquires information regarding the characteristics of the replaced sheet pressure sensors 3 to 6 (step S112). Information regarding the presence / absence of replacement of the sheet-like pressure sensors 3 to 6 and characteristics can be obtained, for example, by connecting an operation unit capable of inputting information to the control unit 21 and allowing an operator to input necessary information from the operation unit. is there.

Next, the control unit 21 sets the pressure to be applied to the sheet pressure sensors 3 to 6 based on the acquired information (step S113). Then, the pressurizing motor 101 is driven and the screw-in type pin 81 is screwed in until the set pressurizing force reaches a designated position where it is considered that the pressurizing sheets 3 to 6 are applied (step S114).

After the screw-in type pin 81 reaches the designated position, the control section 21 calculates the pressure applied to the sheet-shaped pressure sensors 3 to 6 based on the signals output from the sheet-shaped pressure sensors 3 to 6. (Step S115). Then, it is determined whether or not the detected pressure matches the set pressure (step S116), and when the detected pressure and the set pressure match (step S116: Ye
s), the adjustment of pressurization is completed. If the detected pressure and the set pressure do not match (step S1
16: No), the pressurizing motor 101 is driven again.

According to the second embodiment described above, an appropriate pressure can be automatically applied to the sheet pressure sensor. Therefore, the process of applying a pressure to the sheet-shaped pressure sensor can be simplified, and the hand finger can be promptly restarted after the sheet-shaped pressure sensor is replaced.

The present invention is not limited to the above-described first and second embodiments. For example,
The joint plate of the hand finger of the present invention is not limited to the U-shaped joint plate, and the joint plate shown in FIGS.
It may be one shown in. The joint plate 121 shown in FIG. 12 is attached to the finger portion 1 and the hand finger base portion 2 and has a V-shaped cross section along the attached surface.

The joint plate 121 shown in FIG.
According to the above, not only the detection sensitivity in the gripping direction and the insertion force direction is enhanced, but also by arranging the center line CL passing through the center C of the V-shape on the center line that bisects the support surface S in the Y direction. When a force is applied, the balance of pressure applied to each sheet-like pressure sheet-like pressure sensor is made equal, and it is possible to easily maintain the linearity of the gripping force and the inserting force.

The joint plate 131 shown in FIG.
Are attached only to one surface of the finger portion 1 and the hand finger base portion 2. According to the joint plate 131 shown in FIG. 13, the same effect as the U-shaped joint plate is obtained, and the number of parts is further reduced,
This can contribute to reduction in size and weight of the hand finger.

Further, the limiter of the present invention is not limited to the configurations described in the first and second embodiments, but may be configured as shown in FIGS. 14 and 15, for example. The limiter pin 141 is composed of a screw-in type fixing portion 141b for fixing to the hand finger base portion 2 and a protruding portion 141a protruding to the upper surface of the hand finger base portion 2. The limiter pin 141 can be attached to the hand finger base 2 regardless of the type of the sheet-like pressure sensor incorporated because it has the screw-in type fixing portion 141b.

The limiter pin 151 shown in FIG. 15 includes a screw-in type fixing portion 151b similar to the limiter pin 141, and further includes an automatic load adjusting mechanism 152 in which the screw-in type fixing portion 151b is automatically screwed by a motor (not shown). ing. Limiter pin 1 shown in FIG.
According to 51 and the load automatic adjustment mechanism 152, an appropriate limit load can be automatically adjusted according to the type of the sheet-like pressure sensor incorporated in the hand finger.

[0077]

As described above, the invention according to claim 1 is based on the value and distribution of the pressure detected by the sheet-like pressure detecting means inserted between the finger portion and the supporting surface. Since the force applied to the finger portion is detected, it can be directly detected that the finger portion grips the work, and it is not necessary to provide a waiting time. According to the invention described in claim 1, gripping of the work can be accurately detected in a short time. Further, there is an effect that the hand finger can be reduced in size and weight.

According to the second aspect of the invention, since the finger portion and the supporting means are connected by the connecting means having a U-shaped cross section along the attached surface, the direction of holding by the hand finger and the holding by the hand finger are held. There is an effect that the detection sensitivity of the pressure in the two axial directions of the inserted parts can be enhanced and the gripping of the work can be detected more accurately.

According to the third aspect of the present invention, since the finger portion and the supporting means are connected by the connecting means having a cross section along the attached surface, the connecting means has a V-shape. It is possible to enhance the pressure detection sensitivity in the two axial directions of the inserted parts. Further, it is possible to apply pressure in a well-balanced manner to the sheet-shaped pressure detection means and to more accurately detect gripping of the work.

According to the fourth aspect of the invention, since the finger portion and the supporting means are connected by the connecting means provided only on one surface of the finger portion and the supporting means, the direction gripped by the hand finger and the part gripped by the hand finger are It is possible to enhance the pressure detection sensitivity in the two axial directions of the insertion direction. Furthermore, the number of parts of the hand finger can be reduced, and the hand finger can be made smaller and lighter.

According to the fifth aspect of the present invention, a pressure can be applied to the pressure detecting means, and the pressure can be detected by using the portion of the pressure detecting means having good linearity. Therefore, the pressure can be accurately detected, and the grip of the work can be accurately detected.

According to the sixth aspect of the present invention, the pressure applied to the pressure detecting means is adjusted so that the pressure detecting means can be replaced even if the pressure detecting means is replaced with another lot or a different kind. There is an effect that an optimum pressurizing force is applied to the pressure detecting means to be used later so that gripping of the work can be detected more accurately.

According to the seventh aspect of the present invention, when the pressure detecting means is automatically exchanged with the pressure detecting means, the pressure detecting means is replaced with that of another lot or different type. Also, there is an effect that the optimum pressurization is automatically applied according to the characteristics of the pressure detecting means used after the replacement, and the gripping of the work can be detected more accurately.

According to the invention described in claim 8, calibration can be easily performed in a plurality of directions by measuring (acquiring) pressure once. For this reason, the time required for recalibration at the time of regular inspection, or when changing the setup or changing the model in the mass production line is shortened.
It is possible to shorten the time required to change the setup and change the model in the mass production line at the time of regular inspection, and it is possible to detect gripping of the work in a short time.

The invention described in claim 9 has an effect that it is possible to prevent the pressure detecting means from being applied with a pressure of a predetermined value or more, and to prevent the pressure detecting means from being damaged.

According to the tenth aspect of the invention, by adjusting the pressure limited by the limiter means, it is possible to prevent the pressure detecting means from being damaged even when the type of the pressure detecting means is changed. Produce an effect.

According to the eleventh aspect of the present invention, by adjusting the pressure limited by the limiter means, the pressure can be automatically limited to an appropriate value even when the type of the pressure detecting means is changed. It is possible to more easily prevent the detection unit from being damaged.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a basic configuration of a hand finger according to a first embodiment of the present invention.

FIG. 2 is a block diagram for explaining a configuration of a hand finger according to the first embodiment.

FIG. 3 is a diagram showing a state in which a pressure sheet pressure sensor is taken out from the hand finger of the first embodiment.

FIG. 4 is a flowchart for explaining the calibration performed by the hand finger of the first embodiment.

5 is a diagram showing a configuration in which a U-shaped joint plate is provided on the hand finger shown in FIG.

FIG. 6 is a diagram showing a configuration in which a stepped pin is provided at a sheet pressure sensor installation portion of the hand finger shown in FIG.

FIG. 7 is a diagram showing a limiter pin according to the first embodiment.

FIG. 8 is a diagram for explaining a hand finger according to the second embodiment.

FIG. 9 is a diagram for explaining the basic configuration of a hand finger according to the second embodiment of the present invention.

FIG. 10 is a block diagram for explaining a configuration of a hand finger according to the second embodiment.

FIG. 11 is a flowchart for explaining automatic adjustment of pressurization performed by the hand finger according to the second embodiment.

FIG. 12 is a view showing another example of the joint plate.

FIG. 13 is a diagram showing still another example of the joint plate.

FIG. 14 is a diagram showing another example of a limiter.

FIG. 15 is a diagram showing still another example of a limiter.

[Explanation of symbols]

1 finger part 1a Tip 1b Base part 2 hand finger base 3, 4, 5, 6 sheet pressure sensor 21 Control unit 22 Operation part 23 Hand finger drive 24 memory 51,121,131 Joint plate 61 stepped pin 71,141 Limiter pin 81 screw-in pin 82 insertion hole 91 Automatic pressure adjustment mechanism 101 Pressurizing motor 152 Automatic load adjustment mechanism

Claims (11)

[Claims] 1. A hand finger for gripping a work by a plurality of finger portions, the support means having a support surface for supporting the finger portion, and the finger inserted between the finger portion and the support surface. A sheet-like pressure detecting means for detecting a pressure applied to the supporting surface by a portion, and an applied force detection for detecting a force applied to the finger portion based on the value and distribution of the pressure detected by the pressure detecting means. A hand finger comprising: a means. 2. The finger portion and the supporting means are attached to the finger portion and the supporting means, and the finger portion and the supporting means are connected by a connecting means having a U-shaped cross section along the attached surface. The hand finger according to claim 1. 3. The finger portion and the supporting means are attached to the finger portion and the supporting means, and the finger portion and the supporting means are connected by a connecting means having a V-shaped cross section along the attached surface. The hand finger according to claim 1. 4. The hand finger according to claim 1, wherein the finger portion and the supporting means are connected by connecting means provided only on one surface of the finger portion and the supporting means. 5. The hand finger according to claim 1, further comprising a pressure applying means for applying a pressure to the pressure detecting means. 6. The hand finger according to claim 5, further comprising a pressurization adjusting means for adjusting the pressurization applied to the pressure detection means by the pressurization adding means. 7. The pressurization adjusting means automatically sets the pressurization applied by the pressurization adding means according to the characteristics of the pressure detection means, and based on the pressure detected by the pressure detection means. 7. The hand finger according to claim 6, wherein the set pressure is applied to the pressure detecting means. 8. A plurality of the pressure detecting means are provided, and the applied force detecting means detects the force applied to the finger portion in a plurality of axial directions by using the value and distribution of the pressure detected by each pressure detecting means. The hand finger according to claim 1, further comprising a calibration unit that calibrates the finger portion in the plurality of axial directions based on the detected force. 9. The hand finger according to claim 1, further comprising limiter means for preventing a pressure equal to or higher than a predetermined value from being applied to the pressure detecting means. 10. The hand finger according to claim 9, further comprising limiter adjusting means for adjusting the pressure limited by the limiter means. 11. The hand according to claim 10, wherein the limiter adjusting means automatically adjusts the pressure limited by the limiter means based on the pressure detected by the pressure detecting means. Finger.