Gripping device

Abstract

The purpose of the present disclosure is to provide a technique capable of stably gripping an object when the gripping mechanism is not suitable for gripping the object by sandwiching the object. A gripping device according to the present disclosure is provided with a gripping part that grips an object having a first hole and a second hole. The gripping part is provided with: a first rod-shaped member that positions the object by being inserted into the first hole; and a second rod-shaped member that prevents the object from rotating by being inserted into the second hole (see fig. 4B).

Description

gripping device

[0001] The present disclosure relates to a gripping device.

[0002] Automating work using robots is a useful means for improving work efficiency. The tasks performed by robots vary depending on the object of automation. Robot structures also vary depending on the diverse tasks. A technology related to a workpiece positioning device suitable for transferring workpieces to and from a transport means has been disclosed (see Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2006-341327

[0004] Automated assembly equipment used in manufacturing processes may grip and transport a wide variety of assembly objects using a gripping device at the tip of a manipulator. Because the gripping mechanism can only grip a limited number of object shapes, it is necessary to modify the gripping mechanism to match the object shape. For example, if the gripping mechanism cannot grip the object by clamping it, it is necessary to configure at least one of the gripping mechanism or the object so that it can be gripped by a method other than clamping. Furthermore, when gripping by a method other than clamping, it is necessary to fix the relative position and orientation between the gripping mechanism and the object. It appears that Patent Document 1 does not fully consider the means for gripping such objects.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a technology that can stably grasp an object when the grasping mechanism is not suitable for grasping the object by clamping it.

[0006] The gripping device of the present disclosure includes a gripping portion that grips an object having a first hole and a second hole, and the gripping portion includes a first rod-shaped member that positions the object by being inserted into the first hole, and a second rod-shaped member that prevents rotational movement of the object by being inserted into the second hole.

[0007] The gripping device according to the present disclosure can stably grip an object in a situation where it is not suitable to grip the object by pinching it. Problems, configurations, advantages, etc. other than those described above will become clear from the description of the following embodiments.

[0008] 1 is a side view showing a scene in which the gripping device 1 is used. FIG. 2 is a front view of the gripping device 1. FIG. 3 is a top view of the object 2. FIG. 4 is a side view showing an intermediate process of the gripping device 1 gripping the object 2. FIG. 5 is a side view showing an intermediate process of the gripping device 1 gripping the object 2. FIG. 6 is a diagram explaining the roles of second rod-shaped members 12a and 12b. FIG. 7 is a diagram explaining the shapes of the tips of the second rod-shaped members 12a and 12b.

[0009] 1 is a side view showing a scene in which a gripping device 1 is used. The gripping device 1 is a device that grips an object 2. The gripping device 1 is attached to the tip of a manipulator 4. When the gripping device 1 grips the object 2, the manipulator 4 transports the object 2 and the gripping device 1 toward a destination 3.

[0010] It is desirable that the gripping device 1 stably grip the object 2 while transporting the object 2. In other words, it is desirable that the relative position between the gripping device 1 and the object 2 is fixed and the relative attitude between the gripping device 1 and the object 2 is fixed while the gripping device 1 is gripping and transporting the object 2. For example, it is desirable that the object 2 does not rotate while the gripping device 1 is gripping the object 2.

[0011] One possible method for the gripping device 1 to grip the object 2 is to sandwich the object 2 between two members. However, depending on the properties of the object 2, pinching may have adverse effects. For example, if the object 2 is fragile, pinching may cause damage to the object 2. Alternatively, due to equipment constraints, it may be necessary to reduce the size and weight of the gripping device 1, making a pinching-type gripping method unsuitable. In this embodiment, a method is provided that can appropriately grip even such an object 2.

[0012] 2 is a front view of the gripping device 1. The gripping device 1 includes a first rod-shaped member 11, second rod-shaped members 12a and 12b, and a flange 13. The first rod-shaped member 11 and the second rod-shaped members 12a and 12b are rod-shaped members arranged to protrude from the tip surface of the flange 13 along the extension direction of the flange 13.

[0013] Figure 3 is a top view of the object 2. The object 2 has a structure suitable for being grasped by the grasping device 1. Specifically, the object 2 has a first hole 21 and second holes 22a and 22b. The first hole 21, second holes 22a, and second holes 22b are aligned on the same straight line. The cross section AA of Figure 3 will be described later.

[0014] Fig. 4A is a side view showing an intermediate process of the gripping device 1 gripping the object 2. Fig. 4A corresponds to the AA cross-sectional view of Fig. 3. When gripping the object 2, the gripping device 1 descends from above the object 2. The gripping device 1 moves after positioning itself so that (a) the first rod-shaped member 11 is inserted into the first hole 21, (b) the second rod-shaped member 12a is inserted into the second hole 22a, and (c) the second rod-shaped member 12b is inserted into the second hole 22b.

[0015] 4B is a side view showing an intermediate process of the gripping device 1 gripping the object 2. As the gripping device 1 descends toward the object 2 following the process shown in FIG. 4A, the first rod-shaped member 11 is fully inserted into the first hole 21 (the tip of the first rod-shaped member 11 reaches the bottom of the first hole 21), and the tip portions of the second rod-shaped members 12a and 12b are inserted into the second holes 21a and 21b, respectively. In other words, the rod-shaped members and holes are positioned such that when the first rod-shaped member 11 is fully inserted into the first hole 21, the tip portions of the second rod-shaped members 12a and 12b are also inserted into the second holes 22a and 22b, respectively.

[0016] The right diagram in Fig. 4B is a bottom view of the first rod-shaped member 11. A protruding member 111 is attached to the tip of the first rod-shaped member 11. The protruding member 111 is configured to be able to protrude from the side surface of the first rod-shaped member 11 along the radial direction of the first rod-shaped member 11. When the first rod-shaped member 11 is fully inserted into the first hole 21, the protruding member 111 protrudes from the side surface of the first rod-shaped member 11. The right diagram in Fig. 4B shows this process.

[0017] As the protruding members 111 protrude, they come into contact with the inner wall of the first hole 21, thereby pressing the first rod-shaped member 11 against the inner wall of the first hole 21, making it possible to grasp the object 2 from inside the first hole 21. Although three protruding members 111 are arranged in Fig. 4B, at least two are sufficient, and four or more may be provided.

[0018] From the viewpoint of inserting the first rod-shaped member 11 into the first hole 21, the diameter of at least the tip of the first rod-shaped member 11 is smaller than the diameter of the first hole 21. Similarly, from the viewpoint of inserting the second rod-shaped member 12a into the second hole 22a, the diameter of at least the tip of the second rod-shaped member 12a is smaller than the diameter of the second hole 22a. The same is true for the second rod-shaped member 12b.

[0019] 5 is a diagram illustrating the role of the second rod-shaped members 12a and 12b. When the protruding member 111 protrudes and the first rod-shaped member 11 grips the object 2, there is a possibility that the object 2 will rotate around the first rod-shaped member 11. The second rod-shaped members 12a and 12b have the role of preventing such rotation.

[0020] Specifically, when the tip of the first rod-shaped member 11 is inserted into the first hole 21 (i.e., when the protruding member 111 is inserted into the first hole 21), the tips of the second rod-shaped members 12a and 12b are also inserted into the second holes 22a and 22b. As a result, the second rod-shaped member 12a, the first rod-shaped member 11, and the second rod-shaped member 12b are aligned in this order on the same straight line, preventing rotational movement around the first rod-shaped member 11. Therefore, the object 2 can be stably grasped while preventing rotational movement as indicated by the arrow in Figure 5.

[0021] FIG. 6 is a diagram illustrating the shape of the tips of the second rod-shaped members 12a and 12b. The second rod-shaped members 12a and 12b do not necessarily need to be completely inserted into the second holes 22a and 22b; it is sufficient if only a portion of the tip is inserted into the second holes 22a and 22b. This is because the purpose of the second rod-shaped members 12a and 12b is to prevent the rotational movement described in FIG. 5. Therefore, the second rod-shaped members 12a and 12b may be shorter than the first rod-shaped member 11. In the example shown in FIG. 6, the second rod-shaped members 12a and 12b are approximately the same length, and when the first rod-shaped member 11 is completely inserted into the first hole 21, only the tip of each of the second rod-shaped members 12a and 12b is inserted into the second holes 22a and 22b, respectively.

[0022] Because the second rod-shaped member 12a serves to prevent the object 2 from rotating, it is desirable to prevent the relative position between the second rod-shaped member 12a and the object 2 from changing when the second rod-shaped member 12a is inserted into the second hole 22a. For example, the tip of the second rod-shaped member 12a is configured to be thinnest at the tip and gradually thicken toward the base. The diameter of the thickest part of the tip of the second rod-shaped member 12a is larger than the diameter of the second hole 22a. The thin tip of the second rod-shaped member 12a allows the second rod-shaped member 12a to be smoothly inserted into the second hole 22a. Furthermore, the thick part of the tip of the second rod-shaped member 12a comes into contact with the inner wall of the second hole 22a, preventing the relative position between the second rod-shaped member 12a and the object 2 from changing, allowing the object 2 to be stably grasped. The second rod-shaped member 12b also exerts a similar effect.

[0023] The shape of the tip of the second rod-shaped member 12a and the shape of the opening of the second hole 21a do not necessarily have to be identical or similar, as long as they are shapes that allow at least the tip of the second rod-shaped member 12a and the inner wall of the second hole 21a to come into contact with each other. The same applies to the second rod-shaped member 12b. In the example of Figure 6, both the tip of the second rod-shaped member 12a and the opening of the second hole 21a are circular, and the diameter of the thicker part of the tip of the second rod-shaped member 12a is larger than the opening diameter of the second hole 21a.

[0024] The tip of the second rod-shaped member 12a can be configured, for example, as a spherical shape, so that it is thinnest at the tip and becomes thicker toward the base. It does not necessarily have to be a strict sphere, and can be, for example, an elliptical spherical shape. In other words, the tip of the second rod-shaped member 12a can be formed by a curved surface, at least a portion of which can be rotationally symmetric. The same applies to the second rod-shaped member 12b.

[0025] <Embodiment 2> In the first embodiment, three protruding members 111 are arranged along the outer periphery of the side surface of the first rod-shaped member 11. In this case, it is desirable that the angular intervals between each protruding member 111 be uniform (i.e., the protruding members 111 are arranged every 120° in the right diagram of FIG. 4B ). Arranging three protruding members 111 has the advantage of making it easier to align the central axis of the first rod-shaped member 11 with the central axis of the first hole 21. If there were two protruding members 111, it would be difficult to stably fix the first rod-shaped member 11, which could make it difficult to align the central axis. If there were four or more protruding members 111 (i.e., an excessively large number), the protruding amount of each protruding member 111 would be more likely to vary, which could make it more difficult to align the central axis. Therefore, it is considered desirable to have approximately three protruding members 111.

[0026] In the first embodiment, the description has been given of one first rod-shaped member 11, but two or more first rod-shaped members 11 may be used to grasp the object 2. However, if two or more first rod-shaped members 11 are provided, the weight and size of the grasping device 1 increase accordingly, and therefore, if these constraints are imposed on the grasping device 1, it is desirable to have as few first rod-shaped members 11 as possible. For example, if a clamping-type grasping device cannot be used due to spatial or weight constraints, it is considered desirable to have only one first rod-shaped member 11.

[0027] In the first embodiment, the tip of the second rod-shaped member 12a does not necessarily have to have a curved surface shape, as long as it is thin at the tip and gradually thickens toward the base. For example, it may have a tapered shape such as a cone or pyramid. An advantage of using a curved surface shape is that it can suppress damage to the wall of the second hole 22a when the second rod-shaped member 12a and the second hole 22a come into contact. The same applies to the second rod-shaped member 12b.

[0028] In the first embodiment, when the tip of the first rod-shaped member 11 is inserted into the first hole 21 and reaches the bottom of the first hole 21 (the state shown in FIG. 4B ), the tip of the second rod-shaped member 12a is positioned slightly above the bottom of the second hole 22a. This is not necessarily limited to this, and the tip of the second rod-shaped member 12a may also be configured to reach the bottom of the second hole 22a (i.e., the lengths of the first rod-shaped member 11 and the second rod-shaped member 12a are configured to be approximately equal). However, in order to precisely align the tip positions of the rod-shaped members when they reach their lowest positions, appropriate manufacturing precision and control precision are required (e.g., if the object 2 and the gripping device 1 are tilted relative to each other, the tip positions will not be aligned). Therefore, it is preferable to allow the tip of the second rod-shaped member 12a to be positioned slightly above the bottom of the second hole 22a when the tip of the first rod-shaped member 11 reaches the tip of the first hole 21. The same applies to the second rod-shaped member 12b.

[0029] In the first embodiment, the lengths of the second rod-shaped members 12a and 12b do not necessarily have to be the same; one may be shorter than the other. For example, if the second rod-shaped member 12a is longer than the second rod-shaped member 12b, the gripping device 1 is positioned by first aligning the first rod-shaped member 11 and the second rod-shaped member 12a with the first hole 21 and the second hole 22a, respectively. This is because these two members contact the object 2 before the second rod-shaped member 12b. Positioning between the second rod-shaped member 12b and the second hole 22b is performed under the assumption that the two preceding rod-shaped members have been positioned, so they are generally already aligned. In other words, if one of the second rod-shaped members 12a and 12b is longer than the other, it is sufficient to first position the two rod-shaped members and the two holes. This has the advantage of making positioning easier than positioning all three rod-shaped members and all three holes simultaneously.

[0030] In the first embodiment, the provision of second rod-shaped members 12a and 12b has been described, but only second rod-shaped member 12a (or 12b) may be provided. However, providing only one second rod-shaped member places a heavy burden on the gripping device 1 when gripping the object 2, so it is desirable to provide two second rod-shaped members. It is also possible to provide three or more second rod-shaped members, but this will increase the size and weight of the gripping device 1 accordingly, so it is noted that the number of second rod-shaped members must be set within an allowable range.

[0031] In the first embodiment, it has been described that the first holes 21 to the second holes 22b are aligned in a straight line. Alternatively, for example, these holes may be aligned in a curved line. However, there may be restrictions on the positions and areas on the object 2 where these holes can be provided. If they are aligned in a straight line, the object 2 can be grasped without being subject to such restrictions as much as possible. This is because the area occupied by a straight line is small. Furthermore, aligning the holes in a straight line is also desirable from the viewpoint of ease of manufacturing.

[0032] It should be noted that the configurations described in this embodiment can also be used in combination.

[0033] <Regarding Modifications of the Present Disclosure> The present disclosure is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present disclosure, and it is not necessary to include all of the configurations described. Furthermore, a part of one embodiment can be replaced with a configuration of another embodiment. Furthermore, a configuration of another embodiment can be added to a configuration of one embodiment. Furthermore, a part of the configuration of each embodiment can be added to, deleted from, or substituted for a part of the configuration of another embodiment.

[0034] In the above embodiment, it has been described that the first rod-shaped member 11 includes the protruding members 111, and that the protruding members 111 grip the object 2 by protruding. Other gripping mechanisms may be used instead of or in combination with the protruding members 111. For example, a similar gripping function can be provided by other mechanisms in which the first rod-shaped member 11 expands along the radial direction.

[0035] 1: gripping device 11: first rod-shaped member 12a: second rod-shaped member 12b: second rod-shaped member 2: object 21: first hole 22a: second hole 22b: second hole

Claims

1. A gripping device including a gripping part configured to grip an object having a first hole and a second hole, The gripping portion is a first rod-shaped member that is inserted into the first hole to determine relative positioning between the grip portion and the object; a second rod-shaped member that is inserted into the second hole to prevent relative rotation between the grip portion and the object; Equipped with the object has a third hole; the gripping portion includes a third rod-shaped member that is inserted into the third hole to prevent relative rotation between the gripping portion and the object; the second rod-shaped member is longer than the third rod-shaped member, and is configured so that when the gripping device grips the object, the second rod-shaped member comes into contact with the object before the third rod-shaped member does; When gripping the object, the gripping device first positions the first rod-shaped member relative to the first hole, and also positions the second rod-shaped member relative to the second hole, and then positions the third rod-shaped member relative to the third hole. A gripping device characterized by:

2. The first rod-shaped member is configured to expand in a radial direction of the first rod-shaped member after being inserted into the first hole.

2. The gripping device according to claim 1.

3. The second rod-shaped member has a portion whose diameter increases from the front end to the rear end of the second rod-shaped member, and is configured to be inserted into the second hole from the front end of the second rod-shaped member.

2. The gripping device according to claim 1.

4. a tip end of the first rod-shaped member has a protruding member configured to be protruding from a surface of the first rod-shaped member along a radial direction of the first rod-shaped member; The first rod-shaped member is configured to expand in a radial direction of the first rod-shaped member after being inserted into the first hole, by the protruding member protruding from a surface of the first rod-shaped member.

3. The gripping device according to claim 2.

5. The first rod-shaped member has three of the protruding members along the outer periphery of the first rod-shaped member.

5. The gripping device according to claim 4.

6. The gripping device according to claim 5, wherein the protruding members are arranged at 120° intervals along the outer periphery of the first rod-shaped member.

7. the portion is at least partially constituted by a rotationally symmetric curved surface, The diameter of the curved surface is greater than the diameter of the second hole.

4. The gripping device according to claim 3.

8. The first rod-shaped member and the second rod-shaped member are configured such that when a tip of the first rod-shaped member is inserted into the first hole and reaches a bottom surface of the first hole, a tip of the second rod-shaped member is also inserted into the second hole.

2. The gripping device according to claim 1.

9. The first rod-shaped member and the second rod-shaped member are configured such that when a tip of the first rod-shaped member is inserted into the first hole and reaches a bottom surface of the first hole, a tip of the second rod-shaped member reaches a bottom surface of the second hole or is positioned above the bottom surface of the second hole.

9. The gripping device according to claim 8.

10. the first hole, the second hole, and the third hole are aligned on the same straight line, The first rod-shaped member, the second rod-shaped member, and the third rod-shaped member are configured such that when a tip of the first rod-shaped member is inserted into the first hole, a tip of the second rod-shaped member is inserted into the second hole at the same time, and further, a tip of the third rod-shaped member is inserted into the third hole at the same time.

2. The gripping device according to claim 1.