JPH05154784A - Electric connector - Google Patents

Abstract

PURPOSE:To simplify the positioning of electrodes, shorten the stroke of the electrodes for connection, and connect and separate them in a short time by utilizing the elastic deformation of an elastic contact member having an undulated cross section to connect the electrodes. CONSTITUTION:An elastic contact member 8 having an undulated cross section and provided between opposite faces of a pair of electrodes 3, 4 is elastically deformed so that irregularities of ridges and valleys are made flat when the electrodes 3, 4 are moved near to each other. The ridges and valleys of the elastic contact member 8 are tightly pressed to the opposite faces of the electrodes 3, 4 by the elastic reaction generated by the elastic deformation. The electrodes 3, 4 can be excited or de-excited by the elastic contact member 8 when they are merely moved near or apart. Abrasion-resistant materials 6, 7 are provided on the electrodes 3, 4 to be butted together, thus the abrasion of the electrodes 3, 4 is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic tool changer for use in, for example, industrial robot hands.
The present invention relates to an electrical connector incorporated for electrical connection between a fixed plate on a robot side and a tool plate on which a tool is mounted.

[0002]

2. Description of the Related Art An arm of an industrial robot is equipped with an automatic tool changer for changing a tool for machining. This automatic tool changer is capable of aligning and connecting a tool plate in which a tool is integrated with a fixed plate connected to an arm of a robot.
An example of such an automatic tool changer is disclosed in Japanese Utility Model Laid-Open No. 3-43174.

The fixed plate and the tool plate can be joined and separated by a mechanical means such as a lock pin, and the machining of the work is automatically continued while exchanging the tool plate with a tool as required. You can do it. Then, in order to energize the tool mounted on the tool plate, it is usual to provide both the fixed plate and the tool plate with an electrical connection structure. A connector is used for this connection, but in the case of a tool that performs heavy cutting using a large robot, the current used is also large,
Each has its own connector.

In the case of an automatic tool changer, the fixed plate and the tool plate are joined by abutting their respective axes. Therefore, it is necessary to use a connector adapted for such a coupling method also for electrical connection, and conventionally, the connector shown in FIG. 6 is generally used.

FIG. 6A shows a pressing type in which a movable electrode 52 and a fixed electrode 53 are incorporated in a fixed plate 50 on the robot hand side and a tool plate 51 on which a tool can be mounted, respectively. Is. The movable electrode 52 is fixed to the fixed plate 50 by the spring 52a.
Is urged toward the outside of.

In the pressing type connector, the fixed plate 50
When connecting the tool plate 51 with the movable electrode 52
The facing surfaces of the fixed electrode 53 and the fixed electrode 53 are joined together, and the joining force is maintained by the biasing force of the spring 52a.

In such a pressing type, the movable electrode 5
Since the opposing surfaces of 2 and the fixed electrode 53 are only brought into pressure contact with each other in the overlapping direction, the degree of freedom in positioning in the plane coordinates orthogonal to the coupling axis of the fixed plate 50 and the tool plate 51 is relatively high. Therefore, the structure is relatively simple and the durability is good, and the stroke of the fixing plate 50 in the coupling direction is short.
The attachment and detachment with 1 can be done quickly. In particular, since the connection can be performed with a short stroke, the moving amount of the movable electrode 52 can be reduced, and as a result, the bulk of the tool plate 51 in the axial direction is also reduced, which is suitable for a robot hand.

On the other hand, FIG. 6B shows an insertion type, in which a fixed electrode 54 is provided on a fixed plate 50, which is opposite to the pressing type. As can be seen from the comparison with the fixed type, the fixed electrode 54 has a length that considerably protrudes from the tip of the fixed plate 50, and an electrode 55 that receives the fixed electrode 54 is provided on the tool plate 51 side. This electrode 5
5 includes a sleeve 55a into which the fixed electrode 54 is inserted, and a plurality of springs 55b made of metal are housed inside the sleeve 55a. The spring 55b has an arcuate shape as shown in the figure, and is elastically deformed when the fixed electrode 54 is inserted into the protruding portion, and strongly contacts the outer peripheral surface of the fixed electrode 54.

In this insertion type, the fixed plate 50
Since the fixed electrode 54 and the spring 55b slide with each other each time the tool plate 51 is attached and detached, there is an advantage that the contact surface can be cleaned and a good conduction state can be maintained. Further, by increasing the diameter of the fixed electrode 54 and increasing the number of springs 55b, it is possible to cope with a large current, and since there are a plurality of springs 55b, there are multiple contacts, so contact failure due to dust or the like does not occur. ..

As described above, both the pressing type and the insertion type have their own unique advantages, and stable electrical connection can be realized by appropriately selecting them according to the application and incorporating them into the apparatus. it can.

[0011]

However, in the pressing type, since the movable electrode 52 and the fixed electrode 53 have only a single contact point where they are in contact with each other, contact failure is likely to occur if dust or the like enters the contact surface. .. Moreover, since the contact surfaces of the movable electrode 52 and the fixed electrode 53 only abut against each other in the axial direction, the cleaning action can hardly be realized. Therefore, the oxide film on the surface of the electrode is more likely to be affected, and there is a problem in that the current flow becomes defective. Further, in order to increase the current, the outer diameters of the movable electrode 52 and the fixed electrode 53 may be increased, but the volume occupied in the tool plate 50 also increases. For this reason, it is not suitable for a tool changer in which small size and light weight are important in design.

Further, in the case of the insertion type, it is necessary to strictly position the fixed electrode 54 when the fixed electrode 54 is inserted into the sleeve 55a of the electrode 55 on the tool plate 51 side. Therefore, the dimensional accuracy of the fixed electrode 54 and the electrode 55 and the accuracy of attachment to the fixed plate 50 and the tool plate 51 are required to be high, which is a problem in terms of manufacturing and maintenance. Furthermore, when inserting the fixed electrode 54 into the sleeve 55a and when removing it from the sleeve 55a, a large load is applied to the fixed electrode 54 and the electrode 55.
It is necessary to prevent this from happening. For this reason, the fixing plate 50 and the tool plate 51 are carefully joined and separated, which results in time consuming.

As described above, although the pressing type and the insertion type have their respective advantages, there are unavoidable obstacles. And such a problem has arisen not only in the field of the automatic tool changer, but also in the electrical connection portion of various other devices.

An object to be solved in the present invention is to provide an electrical connector which can always maintain a stable contact state, can be easily connected and disconnected, and does not require high manufacturing precision.

[0015]

SUMMARY OF THE INVENTION The present invention is an electrical connector comprising a pair of electrodes in a posture in which their conducting surfaces face each other, and is capable of electrically conducting to each other by relative movement of these electrodes, An arrangement in which a corrugated elastic contact member is interposed between the opposed surfaces of the pair of electrodes, and the peaks of the corrugated elastic contact member are abutted against the opposed surface of one electrode and the valleys are opposed to the opposed surface of the other electrode. It is characterized by

A biasing means such as a spring for pressing the elastic contact member between the electrodes may be provided so that the elastic contact member properly contacts the electrodes.

Further, a wear-resistant material protruding outside the facing surface is provided at the edge of the facing surface of one of the pair of electrodes, and one electrode is provided at the facing surface of the other electrode. It is also possible to incorporate an antiwear material opposite the antiwear material.

Further, a leaf spring can be used as the corrugated elastic contact member, and the leaf spring may be formed as a backbone having a longitudinal direction and a large number of branches branched in the width direction from the backbone. ..

[0019]

The elastic contact member having a wavy cross section interposed between the facing surfaces of the pair of electrodes elastically deforms so that the peaks and troughs of the waves become flat when the electrodes approach each other. And
Due to the elastic reaction force generated during this elastic deformation, the ridges and valleys of the elastic contact member are tightly pressed against the facing surfaces of the electrodes.
Therefore, conduction and non-conduction can be achieved by the elastic contact member simply by bringing the electrodes closer to or farther from each other.

Further, abrasion resistance of the electrodes is prevented by providing the electrodes with a wear resistant material and abutting them against each other. Then, by holding the end of the elastic contact member in the running direction of the wave peaks and troughs as the free end on the wear resistant material provided on one electrode, the wave peaks and troughs are elastically contracted when the electrodes are brought close to each other. The pitch of will expand. Therefore, the facing surface of the electrode, which is in contact with these peaks and valleys, is cleaned by sliding, and good conduction is maintained.

Further, the wavy elastic contact member is a leaf spring,
If a trunk running in the longitudinal direction and a large number of branches extending in the width direction are provided in a wavy shape, a large number of electrical contacts can be provided.

[0022]

FIG. 1 is a sectional view of the essential parts showing an example in which the electrical connector of the present invention is used to connect a fixed plate and a tool plate of the automatic tool changer described in the conventional example.

In the figure, a robot hand (not shown)
The first electrode 3 and the second electrode 4 are incorporated into the fixed plate 1 attached to the fixed plate 1 and the tool plate 2 that is detachable from the fixed plate 1, respectively. The fixed plate 1 attached to the robot hand is a tool plate 2 which is placed on a dedicated rack or the like and can be coupled and separated in the axial direction (the direction of the arrow in the figure). Fixed plate 1 and tool plate 2 by the lock mechanism
Are integrated into the illustrated state.

The first electrode 3 is movably incorporated in the tool plate 2 in a direction parallel to the connecting axis when the fixed plate 1 is connected, and is biased by a spring 5 in a direction projecting from the fixed plate 1 in the connecting direction. There is. Meanwhile, the second
The electrode 4 is integrally fixed to the tool plate 2. The lead wires 3a and 3a are respectively connected to the first and second electrodes 3 and 4.
4a is connected, and the lead wires 3a and 4a of the robot hand side and the tool side are connected.

The first electrode 3 and the second electrode 4 have, for example, a cylindrical shape, and their opposing surfaces are formed to have the same shape. Then, wear-resistant materials 6 and 7 made of, for example, resin or ceramics are attached to the edges of the facing surfaces. Then, the first electrode 3 and the second
The leaf spring 8 is incorporated as an elastic contact member in order to establish electrical connection with the electrode 4.

FIG. 2 is a perspective view showing the leaf spring 8, and FIG. 3 is shown in FIG.
2 is a vertical sectional view taken along the line AA of FIG.

The leaf spring 8 is manufactured by a punching press using a conductor metal having an appropriate thickness as a material.
It has a pattern in which a trunk 8a running in the longitudinal direction and a pair of branches 8b extending from the trunk 8a to the left and right are formed in the longitudinal direction at a constant pitch. With such a uniform pattern, the trunk 8a and the branches 8b are formed by using a long material, and the unnecessary branches 8 are cut as shown in FIG.
All you have to do is cut b. Therefore, the leaf spring 8 having a length corresponding to the size of the electrode can be easily manufactured, and the burden on the manufacturing process does not increase.

As shown in FIG. 3, the leaf spring 8 has a corrugated cross-sectional shape in which a trunk 8a is a mountain and branches 8b are provided on the left and right sides thereof with one valley 8c and a mountain 8d. Then, a total of three points of the trunk 8a and the peaks 8d of the branches 8b hit the end surface of the first electrode 3,
The two points of the valley 8c of the branch 8b hit the end face of the second electrode 4 to electrically connect the first electrode 3 and the second electrode 4.

Further, in the illustrated example, the leaf spring 8 is made of the wear-resistant material 6.
It is attached to the first electrode 3 by utilizing the above, and an exploded view is shown in FIG.

A notch 3b for attaching the abrasion resistant material 6 is provided on the surface of the first electrode 3 facing the second electrode 4, and a screw hole 3c is penetrated from the surface facing the fixed plate 1 to the notch 3b. ing. The cutouts 3b are provided at two locations by hollowing out a part of the end face of the first electrode 3, and the wear resistant material 6 is fitted into each of these. And the fixing screw 3d
The anti-wear material 6 is fixed to the first electrode 3 by screwing into the anti-wear material 6 through the screw holes 3c.

The wear-resistant material 6 has a length such that it slightly protrudes from the end face when it is fixed to the first electrode 3, and a holding groove 6a into which both ends of the core 8a of the leaf spring 8 can be inserted is formed in the protruding portion. It is provided. When the base 8a is held by the holding groove 6a and the wear-resistant material 6 is fixed to the first electrode 3, the dimensional relationship is determined so that the valley 8c of the branch 8b projects out beyond the end surface of the wear-resistant material 6.

On the other hand, the abrasion resistant material 7 provided on the second electrode 4 is also attached by the same structure as the abrasion resistant material 6 of the first electrode 3. It is needless to say that the position is aligned with the wear resistant material 6 of the first electrode 3, and the surface facing the wear resistant material 6 is at the same level as the facing surface of the second electrode 4.

Instead of incorporating two pieces of each of the anti-friction materials 6 and 7 like a block, the first and second
If the facing portions of the electrodes 3 and 4 are cylindrical, the wear resistant materials 6 and 7
May be attached as a ring. In this case, since the contact surface between the abrasion resistant materials 6 and 7 expands, the durability of these abrasion resistant materials 6 and 7 improves.

In this way, the plate spring 8 is incorporated as an elastic contact member in the first electrode 3 on the fixed plate 1 side, and when the tool plate 2 is connected to the fixed plate 1, the plate spring 8 is formed.
By fixing the fixed plate 1 to the second electrode 4
Side and the tool plate 2 side are electrically connected.

In the above structure, before the tool plate 2 is connected to the fixed plate 1, the base 8a of the leaf spring 8 and the ridges 8d on the left and right sides thereof are in contact with the first electrode 3 as shown in FIG. The leaf spring 8 has a natural shape that is not elastically deformed at all.

When the tool plate 2 is connected to the fixed plate 1, these plates 1 and 2 move relative to each other in the direction of the arrow in FIG.
Then, when the fixed plate 1 and the tool plate 2 hit each other, the wear resistant material 6 protruding from the end surface of the fixed plate 1 collides with the wear resistant material 7 of the partner. Therefore, even if the tool exchange is repeated many times, only the wear resistant materials 6 and 7 are worn or deformed, and the durability of the first and second electrodes 3 and 4 is significantly improved. Since the first electrode 3 is biased by the spring 5, the leaf spring 8 acts as the second electrode 4.
It is pressurized between and, and connection with an appropriate contact pressure is possible.

The behavior of the leaf spring 8 when the fixed plate 1 and the tool plate 2 are coupled together is as shown in FIG.

In FIG. 5, the first electrode 3 and the second electrode 4 shown in the upper stage are in the initial stage of the coupling of the fixed plate 1 and the tool plate 2, and the two valleys 8c of the leaf spring 8 are the tool plate 2. This is the state at the time of contact with the second electrode 4 of.
Further, the lower fixing plate 1 and the tool plate 2 are completely connected and locked, which corresponds to FIG.

Before coupling, the first electrode 3 is provided with a wear resistant material 6
In the leaf spring 8 attached by, the trunk 8a contacts the first electrode 3 at the point K, and the two peaks 8d contact the first electrode 3 at the point L. Then, as described above, the valley 8c is located at a position protruding beyond the wear-resistant material 6, so that the valley 8c
c comes into contact with the second electrode 4 at the position indicated by M in the figure.

Next, the fixed plate 1 and the tool plate 2
When and approach each other, the distance between the respective facing surfaces of the first electrode 3 and the second electrode 4 decreases, and the leaf spring 8 gradually reduces the undulations of its valleys 8c and peaks 8d. Elastically deforms. Then, when the fixed plate 1 and the tool plate 2 are coupled and locked, the leaf spring 8 is caused by the elastic reaction force of the leaf spring 8 and the biasing force of the spring 5.
Closely contact the opposing surfaces of the first electrode 3 and the second electrode 4. Therefore, the first and second electrodes 3 and 4 are electrically connected to each other by the multiple contacts by the multiple branches 8b.

Further, when the lock is unlocked and the fixed plate 1 and the tool plate 2 are separated from each other, the contracted leaf spring 8 is restored as shown in the lower part of FIG. 5, and the original wave shape is obtained as in the upper part. When the fixed plate 1 and the tool plate 2 are further separated from each other, the electrical connection between the first and second electrodes 3 and 4 is separated.

In such connection or disconnection, it is not necessary to insert the electrode into the mating connection hole as in the insertion type, and the leaf spring 8 may simply be moved so as to come into contact with the second electrode 4. , The degree of freedom in positioning the first and second electrodes 3 and 4 is increased. Therefore, it is possible to give a degree of freedom to positioning of the fixed plate 1 and the tool plate 2 when they are coupled.

The connection between the first and second electrodes 3 and 4 is as follows.
The elastic reaction force when the plate spring 8 elastically contracts due to the approach of the fixed plate 1 and the tool plate 2 is used. Therefore, it suffices that the fixed plate 1 and the tool plate 2 be stroked with each other when they are coupled to such an extent that this elastic reaction force is generated. Therefore, a small stroke is sufficient to elastically deform the corrugated leaf spring 8.
The stroke of the fixed plate 1 and the tool plate 2 can be shortened as compared with the insertion type shown in (b). As a result, the fixed plate 1 and the tool plate 2 when changing the tool
The time to put on and take off is also shortened. Further, since the bulkiness of the tool plate 1 in the connecting direction does not become large, the size and weight can be reduced, and the tool can be suitably used as an automatic tool changer.

In the case of an automatic tool changer having a structure in which skidding occurs at the time of joining, as described in Japanese Utility Model Laid-Open No. 43174/1993, it is necessary to prevent wear and maintain an appropriate contact pressure for a long time. You can

Further, the first and second electrodes 3 and 4 are in multipoint contact with the trunk 8a of the leaf spring 8 and the valleys 8c and peaks 8d of the multiple branches 8b. Therefore, in the case of the pressing type shown in FIG. 6B, one surface contact is likely to cause conduction failure when foreign matter enters, but multi-point contact can prevent such an accident. .. Further, if the plane shapes of the facing surfaces of the first and second electrodes 3 and 4 and the leaf spring 8 are increased, a large current can be supported and a large capacity can be achieved. And
Even in this case, since it is not necessary to increase the length of the first and second electrodes 3 and 4 in the coupling axis direction, coupling and separation with the fixed plate 1 and the tool plate 2 can be performed with a small stroke.

Here, when joining the first and second electrodes 3 and 4, the valleys 8c and the peaks 8d of the leaf spring 8 should be displaced from their initial positions as shown in the lower part of FIG. Move. That is, when the leaf spring 8 contracts, the backbone 8
Since a is constrained by the holding groove 6a of the wear-resistant material 6, it does not move in the width direction, but as the leaf spring 8 contracts, the peak 8d that was in contact with the first electrode 3 at the point L becomes a point. L-1
Similarly, the valley 8c that was in contact with the second electrode 4 at the point M moves to the point m. Therefore, the peaks 8d and the valleys 8c slide on the surfaces of the first electrode 3 and the second electrode 4, respectively, within the range of the arrow in FIG. Such mountain 8d and valley 8
The sliding of c cleans the surfaces of the first and second electrodes 3 and 4 and prevents the contact surfaces from being oxidized. It is needless to say that this cleaning is performed not only when the first and second electrodes 3 and 4 are joined but also when they are separated by sliding in the opposite direction.

As described above, by making the leaf spring 8 wavy, the first electrode 3 and the second electrode 4 of the exchanged tool plate 2 are cleaned every time the fixed plate 1 and the tool plate 2 are exchanged. be able to. Therefore, even when the tool plate 2 having a long interval to be used is mounted, the contact surface of the second electrode 4 is wiped by the sliding of the plate spring 8 at the time of coupling, and good electrical conduction is obtained.

On the other hand, if the abrasion-resistant materials 6 and 7 are made of hard resin or the like, the impact of the first and second electrodes 3 and 4 at the time of joining can be buffered, and not only wear can be prevented but also the members can be prevented. It also helps protect. In addition, since the metal for electrodes is inferior in wear resistance, it is optimal to provide such wear resistant materials 6 and 7 in the case of frequently changing tools.

Further, the abrasion resistant material 6 on the side of the first electrode 3 is also used as a member protruding slightly from the end surface of the first electrode 3 and mounting the leaf spring 8 therein. At this time, the corrugated leaf spring 8 contracts to obtain a good contact pressure, and at the same time,
The clearance is set so that the peaks 8d and the valleys 8c can be moved sufficiently for cleaning. This clearance can be expressed as a distance corresponding to Z in FIG. 4, and it is preferable to optimally set the wall thickness of the leaf spring 8 and the shapes of the peaks 8d and the valleys 8c in accordance with the size of the clearance Z.

For example, if the clearance Z is too small, the corrugation of the leaf spring 8 also becomes small, so that the elastic deformation at the time of coupling becomes small and the proper contact pressure may not be maintained. Therefore, the clearance Z and the leaf spring 8
It is necessary to make the relationship of the size of the wave shape of (3) appropriate so that a sufficient elastic reaction force can be obtained. Even if the clearance Z is not set strictly, the contact pressure is maintained by the elastic deformation of the leaf spring 8. Therefore, unless elastic fatigue occurs, it is difficult to establish a conductive connection between the first and second electrodes 3 and 4. Not at all.

Although the electrical connection of the automatic tool changer has been described above, it goes without saying that the electrical connector of the present invention can be used for the electrical connection of other devices.

[0052]

According to the present invention, since the electrodes are connected by utilizing the elastic deformation of the elastic contact member having the wavy cross section, the positioning of the electrodes can be facilitated and the stroke of the electrodes for connection can be shortened. Connection and disconnection can be done in a short time. Further, since the surface of the electrode can be cleaned by utilizing the movement of the peaks and valleys when the wavy elastic setting member contracts, a good conductive state can always be obtained. Further, by adopting the multi-point contact type, it is possible to maintain the conductive state even if a foreign matter or the like enters, and it is not necessary to select a use environment.

Further, by integrally attaching the anti-wear material to the electrodes and abutting them, the abrasion of the electrodes can be prevented and the durability can be improved even if the connection and disconnection are repeated frequently. Planned.

[Brief description of drawings]

FIG. 1 is a sectional view of essential parts showing an example in which an electric connector of the present invention is provided between a fixed plate and a tool plate of an automatic tool changer.

FIG. 2 is a perspective view of a leaf spring provided as an elastic contact member of an electric connector.

FIG. 3 is a sectional view taken along the line AA of FIG.

FIG. 4 is a schematic exploded view showing attachment of a wear resistant material and a leaf spring to a fixed plate.

FIG. 5 is a diagram showing movement and cleaning of contacts based on elastic deformation of a leaf spring.

FIG. 6 is a cross-sectional view of essential parts showing a conventional electric connector, in which FIG. 6A is a pressing type and FIG. 6B is an insertion type.

[Explanation of symbols]

 1 Fixed Plate 2 Tool Plate 3 First Electrode 4 Second Electrode 5 Spring (Biasing Means) 6 Anti-Abrasion Material 7 Anti-Abrasion Material 8 Leaf Spring (Elastic Contact Member) 8a Core 8b Branch 8c Valley 8d Mountain

Claims (5)

[Claims] 1. An electrical connector comprising a pair of electrodes in a posture in which their respective conducting surfaces are opposed to each other, and is capable of electrically conducting to each other by relative movement of these electrodes,
An arrangement in which a corrugated elastic contact member is interposed between the opposed surfaces of the pair of electrodes, and the peaks of the corrugated elastic contact member are abutted against the opposed surface of one electrode and the valleys are opposed to the opposed surface of the other electrode. The electrical connector characterized in that 2. The electrical connector according to claim 1, further comprising a biasing unit that presses the elastic contact member between the electrodes. 3. An abrasion-resistant material protruding outward from the facing surface is provided at an edge of the facing surface of one of the pair of electrodes, and the facing surface of the other electrode is attached to the one electrode. The electrical connector according to claim 1 or 2, wherein a wear-resistant material facing the provided wear-resistant material is incorporated. 4. The electric connector according to claim 1, wherein the wavy elastic contact member is a leaf spring. 5. The leaf spring comprises a backbone running in a longitudinal direction,
The electrical connector according to claim 4, wherein the electrical connector has a large number of branches branched in the width direction from the backbone.