JP3234110U - Suspension device for suspending manipulator tools - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suspension device having both a rotatable stem and a rotatably locked stem, which is highly stable and durable even in the absence of lubrication. SOLUTION: A suspension device 10 includes a main body 4 and a stem 5 passing through the main body, and the stem is rotatable or expandable and slidable between an extended position and a retracted position. The spring 8 constantly adds thrust to the stem and brings the stem to the extended position. The body is inserted and closed by snapping or pressing the bushing 11 onto the edge of the body itself. When using a bushing with a round hole, the stem rotates freely on the vertical axis with respect to the body. On the other hand, the anti-rotation function of the stem is achieved by making a part of the stem with a non-circular cross section and coupling a bushing with a hole (the shape of the hole complements the cross section of the stem) to the body. The bushing with the moving stem is made from a self-lubricating plastic material, avoiding the use of grease or lubricating oil. [Selection diagram] FIG. 4

Description

The present invention relates to a suspension device (also called a shock absorber or level corrector) for suspending manipulator tools such as suction pads and grippers.

In the field of industrial automation, the use of robot arms equipped with one or more suction pads or grippers to move an object is known.

The suction pad is mounted on the end of the robot arm and is connected to an air suction means, which causes a vacuum inside the suction pad to effectively attach the suction pad to the object to be pulled up. At this point, the object can be lifted and displaced to a new removal position. Removal is performed by stopping air suction and by raising the suction pad from the object.

In other applications, pneumatic grippers or electric grippers are used in place of suction pads.

Usually, a suspension device (also called a shock absorber or level corrector) is provided between the robot arm and each suction pad or gripper, and the function of the suspension device is its own on the element that the associated suction pad lifts. It is to be able to hold the position.

For example, the lifting element can also be arched, such as the rooftop of a car that needs to be moved within an automobile factory. In this case, the robot arm is equipped with several suction pads that are arranged to interact with the rooftop of the car. Not all suction pads will be in contact with the element at the same time while in progress approaching the element. This is one of the reasons for the need for a complementary system.

In practice, the suspension device is slidable to the body (eg, to the body) between the body constrained by the end of the robot arm (the end of the arm) and the fully extended and fully retracted positions. It has a stem that is inserted so that it can pass through or expand and contract. The spring acts on the stem to counter the movement towards a full retracted position. The spring applies a constant force to move the stem towards a fully extended position.

The suction pad is constrained to the distal end of the stem and the proximal end of the stem is connected to the outside air suction line (ie, the vacuum line). In fact, to define the air suction channel itself from the suction pad, the suspension device is hollow, i.e. both the body and the stem are hollow. In the case of grippers, the grippers are also constrained to the distal end of the stem and cannot be hollow.

The stem advance between the fully extended position and the fully retracted position coincides with the advance of the robot arm, which allows the device to complement.

Generally, the body and stem of the device are made of anodized aluminum, or steel or brass.

There is a variant in which the stem rotates freely with respect to the device body, such rotation is locked in devices with stems with a non-circular cross section, and the body is rolled to create a special shoulder that prevents the stem from rotating. There is a modified form.

Devices known in the art are affected by some shortcomings that the present invention aims to overcome.

First, the manufacture of both suspension devices with rotatable rods and suspension devices with non-rotatable rods requires an excessively large number of components, i.e., the manufacture of different components and different components. Requires assembly. On the other hand, in order to minimize costs, it is possible to simplify and standardize the fabrication, while making it possible to obtain suspension devices with both rotatable and non-rotatable stems on the basis of a common platform. desirable.

Another drawback is the books currently available to keep the stem sliding with minimal friction and prevent the sliding from generating metal dust that would accumulate on the product to be operated. The device needs to be lubricated on a regular basis. On the contrary, the use of lubricants should be avoided, especially if the suspension device is used to handle food or pharmaceutical products.

An object of the present invention is to provide a suspension device for suspending a manipulator tool that overcomes the limitations of known solutions, effectively suspending a suspension device with both a rotatable stem and a rotatably locked stem. At the same time, it is easy to manufacture so that it is stable and durable even in the absence of lubrication.

Accordingly, in a first aspect, the present invention relates to the device of claim 1 (also referred to as a level corrector or buffer device) for suspending a suction pad, gripper, or other manipulator tool.

Specifically, the device is at least partially within the body, preferably by a single block (ie, made of one element) and, for example, stretchable or through the body. It has a stem to be inserted. The stem is guided through a hole obtained by a guide bushing that is fastened to the end of the body and can slide relative to the body between the extending and retracting positions.

The body is intended to be tightly constrained by a manipulator (eg, a robot arm). The stem advance with respect to the body of the device corresponds to the maximum displacement of the robot arm that allows the device to complement.

An elastic element (eg, a spring) is functionally intervening between the body of the device and the stem, with the task of constantly applying thrust to the stem and bringing the stem to an extended position.

If the device needs to support a suction pad, the device has a hollow that allows air suction from the suction pad constrained by the stem. In other words, the stem has an inner channel that fluidly communicates the suction pads that are constrained to the distal end of the stem, with an outside air suction line that is constrained to the opposite end of the stem (named the proximal end). ..

To provide an advantage, the stem guide bushing can be inserted into each end of the device body by collision, in any case, by snapping or pressing the stem, and the guide bushing is replaceable. The bushing is made in two variants, one with a stem with a circular cross section or a circular guide hole that allows the stem portion to rotate about its vertical axis, and the other with a non-circular cross section. It is accompanied by a non-circular guide hole (eg, polygonal) that prevents rotation of the stem or stem portion with.

This solution simplifies the assembly of suspension devices and makes it possible to optimize the supply of components. In fact, the two variants of the suspension device can be created identically, except for the guide bushing. Therefore, during the assembly step, the operator needs to choose only two bushings. Therefore, the shared criteria for variants of the two suspension devices have been acquired to provide obvious advantages in terms of assembly time and cost by being modular.

The guide bushing is preferably made from a self-lubricating plastic material, thereby avoiding the use of lubricants. For example, a stem made of metal slides directly onto the inner wall of the bushing guide hole.

Further properties and advantages of the present invention will be more apparent by considering the following detailed description of preferred but non-exclusive embodiments, which are used in the accompanying drawings and for purposes of illustration rather than limitation. Shown only for.

FIG. 3 is a perspective view of a suspension device according to a known technique equipped with a suction pad. FIG. 3 is a perspective view of a suspension device according to a known technique equipped with a suction pad that grips an element. FIG. 3 is a perspective view of a suspension device according to a known technique equipped with a gripper. It is an exploded view of the 1st Embodiment of the suspension device according to this invention. It is a vertical (vertical) sectional view of the suspension device shown in FIG. It is an exploded view of the 2nd Embodiment of the suspension device according to this invention. It is an exploded view of the 3rd Embodiment of the suspension device according to this invention. FIG. 7 is a perspective view of the suspension device shown in FIG. 7 in an assembled state.

FIG. 1 shows a suspension device 1 according to a known technique, equipped with a corresponding suction pad 2 and connected to an air suction line 3.

Device 1 (which can also be defined as a buffer device or level corrector) can be inserted through the body 4 and translated with respect to the body, for example, the body 4 which is intended to be constrained to the robot arm using brackets and clamps. The stem 5 is provided. The stem 5 is a penetrating stem, i.e., the stem 5 passes through the entire length of the body 4, at which time the two ends of the stem 5 remain exposed at all times. The lower end (called the distal end) of the stem 5 supports the suction pad 2, and the upper end (called the proximal end) is connected to the air suction line 3. The term "distal and proximal" is chosen relative to the position with respect to the robot arm when using device 1.

Alternatively, the stem 5 also cannot pass through the body 4. For example, the stem 5 can be accommodated in the main body 4 in a stretchable manner.

In device 1, the stem 5 is rotatably locked with respect to the body 4.

FIG. 2 shows a suspension device 1'according to a known technique, equipped with a suction pad 2 for gripping the element P. Unlike the device 1 shown in FIG. 1, in this variant, the stem 5 is rotatable with respect to the body 4 so that the element P can rotate.

FIG. 3 shows another suspension device 1 ″ according to a known technique without the suction pad 2 but equipped with the gripper C. In this case, the body of device 1 ″ is not connected to the compressed air line.

Known techniques provide a complex system for assembling the stem 5 and body 4 of the suspension device, i.e. the manufacturer requires a device with a rotatable stem 5 relative to the body 4 and the body 4 Manufactures need to be distinguished to meet the requirements of devices with non-rotatable stems 5, including manufacturing of different objects 4 and corresponding stems 5 types. In addition, in devices according to known techniques, the stem 5 needs to be lubricated consistently to limit the sliding friction of the body 4 and the formation of metal dust.

FIG. 4 shows an exploded view of a suspension device 10 according to the present invention equipped with a main body 4 and a corresponding stem 5 that is at least partially inserted into the main body 4 so as to slide. The stem 5 is made up of two parts 5'and 5'' that can be tightened together (eg, screwed), or the stem 5 is one with two parts 5'and 5'with different cross sections. Made of elements. The lower 5 ″ includes a distal end 6 to which the suction pad 2 or other tool is screwed, and the upper 5 ″ includes a proximal end 7 to which the suction line 3 is screwed, if necessary.

As described below, the upper 5'' of the stem 5 has a circular cross section and the lower 5'has a non-circular cross section, suitable for preventing the stem 5 from rotating with respect to the body 4. be. As described below, since the stem 5 is made up of two parts 5', 5'' with different cross-sectional shapes, each stem allows or prevents rotation of the stem 5 with respect to the body 4. Therefore, the suspension device does not need to be replaced to reconfigure it.

The device 1 also includes a spring 8 housed in the main body 4 and has a function of counteracting the vertical movement of the stem 5.

FIG. 5 is a vertical cross-sectional view of the fully assembled suspension device 10.

The stem 5 has a hollow inside. The recess 9 defines an inner channel for sucking air, so that air is drawn in by the suction pad 2 and traverses the entire stem 5 and is available in a robot arm where line 3 (eg, body 4 is fastened). It flows out through the line).

In FIG. 5, the stem 5 is shown in its fully extended position, i.e., the distal end 6 is at maximum distance from the body 4. Since the stem 5 is a penetrating stem in a sufficiently extended position, the proximal end 7 is in contact with the body 4 and the spring 8 is also extended. Conversely, in a sufficiently retracted position (not shown), the proximal end 7 is away from the upper edge of the body 4, the spring 8 is compressed, and the distal end 6 is in contact with the lower edge of the body 4.

The spring 8 is preloaded to constantly apply thrust to the stem 5 in order to bring the stem 5 to a fully extended position.

The reference length H indicates the distance traveled by the stem 5. This is a complement of progress that allows the robot arm to have a corresponding margin of displacement towards the gripping position of the moving object. It is just a robot arm that compresses the spring 8. When the suction pad 2 reaches the object to be lifted, it abuts on the object and further possible forward movement of the robot arm towards the object is assisted by the device 1.

To provide an advantage, in the suspension device 10, according to the present invention, the bushing 11 is snapped or pressed against the lower end of the body 4 to guide the stem 5 so that the stem 5 moves accurately with respect to the body 4. Assembly is completed by using at least one bushing 11 made of a plastic material that can be inserted thereby (ie, by collision). The inner surface of the bushing 11 defining the through hole for guiding the stem 5 has a cross section that complements the cross section of the lower portion 5'of the stem 5.

As can be seen from FIG. 4, the lower portion 5'of the stem 5 has a flat shoulder portion 13 that results in a cross section of the stem that is not a perfect circle. Inside the bushing 11, there are two corresponding shoulders 14 that guide the shoulders 13 of the stem 5.

In practice, this arrangement does not force the manufacturer to distinguish between fabrications to provide two types of suspension device 10, the stem 5 is rotatable relative to the body 4, or the stem 5 is the body. Although not rotatable relative to 4, the bushing 11 is simply changed each time using the body 4 described above and the stem 5 described above. Since the stem 5 has an upper circular portion 5'' and a lower compartment 5'with a flat shoulder portion 13, simply mounting a round hole and a bushing 11 with an anti-rotation function allows the stem 5 to rotate. That is, as shown in FIG. 4, by mounting the bushing 11 with the inner shoulder portion 14, prevention of rotation of the stem with respect to the main body 4 is achieved.

By having the bushing 11 which can be manually inserted by snapping or pressing the bushing 11 onto the body 14, the assembly operation is significantly simplified because no tool is required by the operator. In the example shown in FIG. 4, the operator simply needs to insert the spring 8 into the body 4, the stem 5 into the body 4 through the bushing 11, and then through the second bushing 12. The nipple 7 is screwed on at the upper end of the stem 5, and finally the bushings 11 and 12 are pushed into the body 4 of the device 10 without the use of special tools.

For example, bushings 11-12 are provided with knurled or deformable fins on the outside, as shown in the figure.

Preferably, the second bushing 12 that closes the top surface of the body 4 is also made of a plastic material and can be inserted by snapping or pressing the second bushing 12 onto the top edge of the body 4 (ie, by collision). The second bushing 12 also guides the stem 5 and, together with the first bushing 11, keeps the stem 5 coaxial with the body 4.

Preferably the first bushing 11 and more preferably both bushings 11-12 are made from a self-lubricating material (eg, polyethylene terephthalate (PTFE) or polyoxymethylene (POM)). This property avoids the use of lubricants that lubricate the stem 5, which is an important aspect for use in the food and electronics industries where impurities or dust are not allowed.

Having a first bushing 11 and preferably also having a second bushing 12 (which can be inserted by snapping or pressing them into the body 4) provides additional advantages, eg, the purchaser thinks later. To satisfy that, the stem 5 rotates on the vertical axis from a configuration in which the stem 5 is rotatably locked by the manufacturer during assembly and by simply changing only the first bushing 11. Bushings 11-12 can be easily replaced, both by the end user, who can easily reconfigure the device 10 by switching to a possible configuration.

FIG. 6 shows a second embodiment 10'of a suspension device according to the present invention, which is different from the solution 10 shown in FIGS. 4 and 5, and the outside of the main body 4 tightens the main body 4 to an external object by a nut 15. It differs in that it has threads to make it possible and that the stem 5 is rotatable on the vertical axis with respect to the body 4. The first bushing 11 defines a circular guide hole in the non-circular portion 5'of the stem 5.

7 and 8 show yet another embodiment 10'' with a stem 5 anti-rotation feature that differs from the aforementioned solution described and is not intended to directly support the suction pad 2, but the suction pad. The difference is that the holder or clamp holder block 16 is intended to be supported by the stem 5. The distal end 6'of the stem 5 is a bracket for anchoring to the block 16, which allows the block 16 to be fastened to the stem 5 in a swirling manner using the screws 17. Suspension device 10 ″ also provides rotatably locking the stem 5. The shoulder portion 14 of the first bushing 11 and the corresponding flat shoulder portion 13 of the stem 5 are shown. Instead of the nipple 7, a screw 7'with a closing head that closes the top surface of the body 4 and the second bushing 12 is provided.

In the different embodiments described (10, 10', 10 ″), at least the first bushing 11, preferably the second bushing 12, also has the first bushing 11 and the second bushing 12 in the body 4. It can be inserted by snapping or pressing, and thus by collision, but has in common that it can be inserted simply by hand without the use of tools. This allows the bushings 11-12 and stem 5 to be easily replaced not only during the assembly step by the manufacturer but also later by the user. This arrangement not only simplifies and speeds assembly, thereby allowing cost savings, but also makes the structure of the device (10, 10 ″, 10 ″) modular. The reason for this is that the manufacturer uses a common platform (ie, the body 4, stem 5, spring 8, bushing 12, etc. described above) to modify only the first bushing 11 and rotate the rotatable stem 5 or rotate. This is because a device (10, 10', 10'') with any of the potentially locked stems 5 can be acquired.

Claims (11)

Suspension device (10, 10', 10'') for suspending manipulator tools (2, C), which can also be defined as a buffer device or level corrector.
The main body (4) that can be fixed to the manipulator and
A first bushing (11) that can be inserted into the end of the main body (4),
At least partially inserted into the body (4) through the first bushing (11) with respect to both the body (4) and the first bushing (11) between the retracted and extended positions. Sliding with the stem (5),
An elastic means (8) that opposes the movement of the stem (5), and the distal end (6) of the stem (5) can be constrained to the tool (2, C). Prepare,
The suspension device is characterized in that the first bushing (11) is inserted by a collision by snapping or pressing the first bushing (11) onto the corresponding end of the body (4). (10, 10', 10''). The suspension device (10, 10 ′, 10 ″) according to claim 1, wherein the first bushing (11) is replaceable on the main body (4). The suspension device (10, 10 ′, 10 ″) according to claim 1 or 2, wherein the first bushing (11) is made of a self-lubricating plastic material. The first bushing (11) defines a guide hole in the stem (5).
i) The guide hole is circular, and the stem (5) is carved in a cross section whose shape complements the guide hole of the bushing (11), or simply in the circumference of the guide hole of the bushing (11). The stem (5) is rotatable within the guide hole, or ii) the guide hole is non-circular and has at least a portion (5') of the stem (5). ) Has a cross section whose shape complements the guide hole of the bushing (11), whereby the stem (5) is rotatably locked to both the bushing (11) and the body (4). The suspension device (10, 10', 10'') according to any one of claims 1 to 3. The part (5') of the stem (5) slidably inserted through the first bushing (11) is
a) A circular cross section, the portion (5') of the stem (5) to the first bushing (11) and to the body (4) on the vertical axis of the stem (5). A circular cross section, or b) a non-circular cross section, which rotates freely with respect to the stem (5), the portion (5') of the stem (5) with respect to the first bushing (11) and on the vertical axis. A non-circular cross section, which is unlikely to rotate with respect to the body (4) and is guided by the first bushing (11).
The suspension device (10, 10', 10'') according to claim 4. The portion (5') of the stem (5) inserted through the first bushing (11) has at least one flat shoulder (13), the first bushing (11) corresponding. The suspension device (10, 10', 10 ″) of claim 5, comprising an inner flat shoulder (14). The suspension device (10, 10 ′, 10 ″) according to any one of claims 1 to 6, wherein the first bushing (11) is made of polyethylene terephthalate or polyoxymethylene. A second bushing that can be inserted by a collision with one end of the body (4) opposite the end into which the first bushing (11) is inserted by snapping or pressing the second bushing (12). The suspension device (10, 10', 10'') according to any one of claims 1 to 7, comprising (12). The stem (5) passes through the body (4) and is guided by both the first bushing (11) and the second bushing (12), thereby coaxial with the body (4). The suspension device (10, 10', 10'') according to claim 8. One of claims 1 to 5, wherein the elastic means (8) is housed in the main body (4) and comprises a spring functionally interposed between the stem (5) and the main body (4) itself. The suspension device (10, 10', 10'') according to item 1. The moving distance (H) of the stem (5) between the sufficient extending position and the sufficient retracting position coincides with the maximum complementary displacement of the manipulator having the body (4) constrained by the manipulator. The suspension device (10, 10', 10'') according to any one of claims 1 to 10.

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