JP3032679B2 - Remote center compliance device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a remote center compliance for facilitating the insertion operation by absorbing the relative displacement between the insertion member and the insertion target member when performing the insertion operation between the insertion member and the insertion target member. It concerns the device.

[0002]

2. Description of the Related Art Conventionally, a mechanism shown in FIG. 7 has been used as a passive type compliance device used for inserting an insertion member into an inserted member. In FIG. 7, 1 is a moving device, 2 is a gripping hand, 3 is an insertion member, and 4 is an inserted member. The passive compliance device 20 is provided with an elastic member 32 between the fixed plate 11 and the movable plate 12, and when there is a relative displacement between the inserted member 3 and the inserted member 4 in the inserting operation, the elastic member 32 is elastic. The relative displacement is absorbed by the member 32 being elastically deformed,
It becomes possible to insert.

Next, FIG. 8 shows a remote center compliance device generally used in an insertion operation. Three or more elastic members 33 are arranged in the circumferential direction between the fixed plate 11 and the movable plate 12, and the diameter of the support position on the fixed plate 11 is larger than the diameter of the support position on the movable plate 12. ing. The center of rigidity (so-called compliance center) of the remote center compliance device 30 having the above-described configuration is set at the point 50.
Acts to come. That is, when the insertion member 3 comes into contact with the inserted member 4 and starts insertion, a rotational moment is generated so that the compliance center 50 becomes a fixed point in a direction to absorb the relative displacement, and the gripping hand 2 is moved together with the insertion member 3. The movable plate 12 can be moved to perform insertion.

Heretofore, as a compliance device using such a principle, a passive compliance mechanism disclosed in Japanese Patent Application Laid-Open No. 3-92286 and a compliance device disclosed in Japanese Utility Model Application Laid-Open No. 60-4393 have been disclosed. It has been known. The passive compliance mechanism disclosed in Japanese Patent Application Laid-Open No. 3-92286 is one in which a fixed plate and a movable plate are connected by a cylindrical elastic member, and is disclosed in Japanese Utility Model Application Laid-Open No. Sho 60-4393. In some compliance devices, a fixed plate and a movable plate are connected by an elastic material deformed into an arc shape.

[0005]

However, the examples disclosed in Japanese Patent Application Laid-Open No. 3-92286 and Japanese Utility Model Application Laid-Open No. 60-4393 are all based on the application of the basic structure shown in the prior art. As is clear from the principle explanation, since the elastic member for obtaining the compliance function is used as a structural member for connecting the fixed plate and the movable plate, the insertion member and the hand for gripping the insertion member are required. The rigidity of the elastic member itself must be naturally limited in order to support the hanging member and have sufficient strength, and the rigidity of rotation as a compliance function becomes very hard. That is, in general, in the conventional compliance device, after the allowable load of the device is determined, the rotational rigidity is secondarily determined according to the allowable load.

However, in order to move the movable plate via the insertion member during the insertion operation, a large force exceeding the rotational rigidity of the compliance device is required. That is, the rotational moment generated in the direction of absorbing the relative displacement between the inserted member and the inserted member must be larger than the rotational rigidity of the compliance device,
If a sufficient rotational moment cannot be generated, galling may occur during insertion, resulting in unsuccessful insertion or excessive damage to the inserted or inserted parts. is there.

Further, as described above, in the conventional device, since the fixed plate, the movable plate, and the elastic member are integrally formed, the remote center compliance device is manufactured once, and the compliance center, It is impossible to change the rotational stiffness, and therefore, every time the object to be inserted changes, it is necessary to newly prepare a compliance device corresponding to the change.

The present invention advantageously solves the above-mentioned problems of the prior art by a simple method. When the insertion member and the inserted member are inserted, the relative position between the inserted member and the inserted member is reduced. It is an object of the present invention to provide a remote center compliance device that absorbs misalignment and facilitates insertion work.

[0009]

Gist of the present invention SUMMARY OF THE INVENTION, in the remote center compliance mechanism having a function of absorbing the relative error of the fixed plate and the movable plate between the fixed plate and the movable plate, fixed plate and movable The plate is connected by three or more ball joint supporting members, and a plurality of replaceable elastic members are provided .
Fixed joint and movable plate
The support position with the
The point of intersection of the extension of the point support
This is a remote center compliance device, which is located substantially at the same position as the center of the compliance.

[0010]

The present invention will be described below with reference to the drawings. FIG. 1 is a plan view illustrating the present invention, FIG. 2 is a cross-sectional view thereof, and FIG. 3 is an insertion operation diagram using the present invention.

In FIGS. 1, 2 and 3, the fixing plate 1
1 is fixed to the mobile device 1, whereby the entire remote center compliance device 10 is suspended from the mobile device 1. On the movable plate 12, a gripping hand 2 for gripping the insertion member 3 is supported.
Is holding the insertion member 3.

The fixed plate 11 and the movable plate 12 are
The ball joints are connected at three ball joint support members 21 arranged on the plane circumference. The ball joint support member 21 is arranged such that the diameter of the support position on the fixed plate 11 is larger than the diameter of the support position of the movable plate 12, and the intersection on the axial extension line is the center point 50 of the tip of the insertion member 3. It is configured to be located at substantially the same position as. Between the fixed plate 11 and the movable plate 12, a plurality of elastic members 31 are provided in the circumferential direction separately from the ball joint support member 21. Conventionally, this elastic member 31
In order to connect the fixed plate 11 and the movable plate 12, a rubber or the like mainly formed into a special shape is used. However, the present invention is not particularly limited, and any elastic body can be applied. For example, a general compression spring is sufficiently applicable.

Next, an example of an insertion operation using the present invention will be described. The insertion member 3 grasped by the grasping hand 2 is moved by the moving device 1 to an upper portion of the inserted member 4. Like the elastic member 31, the moving device 1 is not particularly limited, and may be, for example, an industrial general-purpose robot.

Subsequently, the insertion member 3 is lowered by the moving device 1 so as to be inserted into and brought into contact with the hole entrance of the inserted member 4. At this time, if there is a relative angular displacement between the insertion member 3 and the inserted member 4, a rotational moment is generated about the point 50 which is the compliance center in this contact.

FIG. 4 is an explanatory diagram showing an insertion state due to the generation of the rotational moment. When the insertion member 3 comes into contact with the hole entrance of the inserted member 4, couples F and F are generated, and a counterclockwise rotation moment M is generated. The rotational moment M is for tilting the insertion member 3 in a direction to absorb the relative displacement between the insertion member 3 and the inserted member 4, and this force is generated by the ball connecting the fixed plate 11 and the movable plate 12. The joint support member 21 is tilted, and the elastic member 31 is
The elastic member 31 is also transmitted to the insertion member 3 and the inserted member 4.
By elastically deforming in the direction to absorb the relative displacement of
Insertion can be performed. At this time, as long as the length of the ball joint support member 21 is constant and the center point of the rotational movement of the movable plate 12 is strictly different from the center where the rotational moment M acts, unless it expands and contracts, It does not impede work.

After the insertion operation is completed, the gripping hand 2 releases the grip of the insertion member 3 and retreats by the moving device 1. At this time, in the remote center compliance device 10, the relative positional relationship between the fixed plate 11 and the movable plate 12 returns to the initial state due to the restoring force of the elastic member 31.

In such a series of insertion operations, when the target operation is a repetition of the same operation, it is possible to use a single compliance device for the same operation. If they are different, the rotational moment generated by the contact between the insertion member 3 and the inserted member 4 is large or small, and in order to succeed in insertion, the relative displacement generated by the contact between the insertion member 3 and the inserted member 4 must be reduced. The rotational moment acting in the absorbing direction must be sufficiently larger than the rotational rigidity of the compliance device, and with a single rigid compliance device, it may be difficult to perform an insertion operation. In this case, the elastic member 31 provided between the fixed plate 11 and the movable plate 12 for obtaining the compliance function is provided.
Is provided so that the rotational rigidity of the entire remote center compliance device of the present invention can be changed.

FIG. 5 is a sectional view showing an example in which the elastic member 31 is replaceable. The elastic member 31 (a coil spring is shown in the figure, but may be of course another leaf spring or an air spring) is positioned by the fixed seats 34 and 35 in a pre-pressed state, and is fixed to the fixed plate 11 and the movable plate 12. It is fixed by the bolts 36 and 37. As mentioned above,
The rotational rigidity of the entire remote center compliance device of the present invention can be changed by changing the rigidity of the elastic member 31 alone, or by changing the mounting position or the number of the elastic member 31. Rigidity can be selected, and it can be applied to any work to be inserted without replacing the compliance device itself.

Further, when the length of the insertion member or the gripping position of the gripping hand is changed, it is necessary to change the position of the compliance center 50. In this case, the ball joint support member 21 is fixed. Plate 11
The position of the compliance center 50 can be changed to any position by moving the position of attachment to the movable plate 12 or the position of attachment to the movable plate 12.

FIG. 6 is a sectional view showing an example in which the ball joint supporting member 21 is movable. The support portion 22 of the ball joint support member 21 with the fixed plate 11 is provided with a feed screw 24, and the feed screw 24 passes through a bracket 26 fixed to the fixed plate 11,
The bracket 26 is fixed from both sides by nuts 28a and 28b. Similarly, a bracket 2 in which a feed screw 25 provided on the ball joint support member 21 is fixed to the movable plate 12 is also used for a support portion 23 with the movable plate 12.
7 and nuts 29a from both sides of the bracket 27,
29b. By rotating the nuts 28a, 29a and the nuts 28b, 29b, the respective support members 22, 23 of the ball joint support member 21 are rotated.
Moves parallel to the directions of arrows 52 and 53 on the fixed plate 11 and the movable plate 12 together with the feed screws 24 and 25. This allows the ball joint support member 21
Is changed, and the position of the compliance center 50 can be changed to an arbitrary position in the arrow 51 direction. That is, even when the insertion member 3 or the gripping hand 2 is changed, the compliance center can be arbitrarily changed, and it is possible to deal with various target members.

As described above, since the elastic member 31 can be replaced and the support position of the ball joint support member 21 can be moved, any work to be inserted can be reliably performed by one remote compliance device. Becomes

Although the drawings illustrating the present invention illustrate the insertion member 3 as a shaft member and the inserted member 4 as a hole member in the insertion operation, this is not particularly specified, and The state, that is, the insertion member may be a hole member and the inserted member may be a shaft member.

[0023]

As described above, according to the present invention, in a precision assembling operation for inserting the insertion member into the insertion member, even if the insertion member and the insertion member are relatively displaced, the deviation can be reliably absorbed. In this case, the insertion operation can be automatically performed, and the operation that required skill can be replaced by a machine, thereby saving labor. In addition, the so-called shrink-fitting operation, in which the hole member on the insertion side is heated and expanded in advance and inserted into the shaft member on the insertion side, can be mechanized, and a remarkable effect can be obtained in terms of safety.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating the present invention.

FIG. 2 is a cross-sectional view illustrating the invention.

FIG. 3 is an insertion operation diagram using the present invention.

FIG. 4 is an explanatory diagram showing an insertion state using the present invention.

FIG. 5 is a sectional view illustrating an elastic member according to the present invention.

FIG. 6 is a cross-sectional view illustrating a ball joint support member according to the present invention.

FIG. 7 is a conceptual diagram of a conventional passive compliance device.

FIG. 8 is a conceptual diagram of a conventional remote center compliance device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 moving device 2 gripping hand 3 insertion member 4 inserted member 10 remote center compliance device 11 fixed plate 12 movable plate 20 passive compliance device 21 ball joint support member 22 support portion 23 support portion 24 feed screw 25 feed screw 26 bracket 27 bracket 28a nut 28b nut 29a nut 29b nut 30 remote center compliance device 31 elastic member 32 elastic member 33 elastic member 34 fixed seat 35 fixed seat 36 bolt 37 bolt 50 compliance center

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-57-168840 (JP, A) JP-A-63-102887 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B23P 19/02 B25J 17/02

Claims (1)

(57) [Claims] 1. A remote center compliance mechanism having a function of absorbing a relative error between a fixed plate and a movable plate between the fixed plate and the movable plate, wherein the fixed plate and the movable plate are supported by three or more ball joint supporting members. A plurality of replaceable elastic members are provided for connection and the ball joint support member is fixed.
The support position for the plate and the movable plate is set to be movable.
As well as the extension of the ball joint support member.
The point is approximately the same as the compliance center at the tip of the insertion member
Remote center compliance device characterized by comprising a location.