JPS63306855A - Machining device capable of controlling tool pressure - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a machining device specifically intended to be fixed to the tip of a robot arm. This machining device can be used in particular for shoe upper carding operations or clipping or other machining operations in technologies different from shoe manufacturing.

[Conventional technology] There are many tools that are fixed to the tip of the robot arm.

For example, cutting and welding tools, gripping tools, paint guns, etc., which are used in many industrial sectors, especially in automobile manufacturing.

However, in some industrial fields, it is difficult to change work performed by humans with tools to work performed by automated machines. This is especially true in industries that use materials of animal or plant origin. This is because the properties of these materials are not strictly constant. therefore,
When manufacturing footwear with molded soles, the lower edge of the upper of the shoe is carded with a hand-held, motor-driven tool before the sole is molded. To speed up this process, a template is applied to the upper of the shoe to protect areas that should not be carded.

[Problems to be Solved by the Invention] In the above carding operation, the operator must hold a motor-driven tool in his hand. The tool is then tilted from the vertical and horizontal directions, typically at a 45 degree angle. Even apart from these points, carding is a relatively tedious task. Therefore, the template is picked up by the cutter and damaged and destroyed within a short period of time. moreover,
When performing carding, the pressure is relatively uniform, but its precision is poor.

Furthermore, to ensure flexibility in the manufacturing process, sole molds must be changed frequently. This requires many adjustments to the template.

If this adjustment is not done carefully, the quality of the product will be adversely affected.

Therefore, the quality of the bond when bonding the sole to the upper of the shoe and the appearance of the footwear thus produced depend on the accuracy of the carding operation.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a machining device that allows automation of some of the machining operations with cutters or similar tools that require the application of relatively constant pressure. In this case, a constant pressure can be applied despite the obstacles that the tool may encounter along its machining path. An object of the present invention is to provide a machining device that can automate the carding operation of shoe uppers.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a machining device of this type, which includes: a tool holder head for mounting a driven rotary tool; and a tool holder head for mounting a driven rotary tool; Attach a strain gauge sensor to the rigid arm that supports the head to measure the
a movable assembly comprising the rigid arm on a movable assembly adjustable in the direction of actual movement of the tool; a support coupled to a tip of a robot arm to support the movable assembly; and a signal from a strain gauge sensor. and a control circuit for controlling the movement of the movable assembly so that the pressure applied by the tool to the workpiece matches the reference value.

The device according to the invention is of a particularly simple construction and can be used for machining parts of complex shape, ie parts whose shape is difficult to define geometrically precisely. For example, rjIJ is a mold for injection molding soles directly onto the upper leather! lI
Can be used for machining lines (called rubber cutting lines).

The adjustment of the pressure exerted by the tool is carried out in the direction of the tool's contact. This regulator automatically follows the reference pressure signal. The actual pressure is detected by a flexible support supporting the tool.

The machining device constructed in this way has a very clean and simple structure and can be used in shoe manufacturing bundles.

In addition to its simplicity, this construction is also extremely durable and durable.

According to a particularly advantageous feature, the means for driving the tool are a motor coupled to the tool by a transmission, of which at least a part of the part between the support and the tool holder head comprises: It is made of flexible cables for transmitting rotational motion.

This feature is important for the accuracy of the pressure tIllllll. This is because the flexible cable, which ensures the transmission of rotational movements from the upstream part of the transmission at the output of the motor or drive means to the head, is subject to pressure IJJwJ. This is because it does not disturb the This pressure control is for carding of the shoe upper and corresponds to an effect of about 1 kilogram. The lightness of the device and its great flexibility are due to the separation of the tool holder head and the support, which makes it possible to considerably reduce the inertia to be controlled.

Particularly in the field of shoe manufacturing bundles, therefore, material properties with relatively low uniformity and/or extra thickness can be used. This pressure! II control can be implemented in a flexible manner and, in particular, can be implemented very quickly.

This flexible transmission is capable of transmitting relatively large torques without having stiffness that is detrimental to control accuracy. This torque is particularly important for tools supported in the tool holder head, such as carding tools, etc.
suitable for the work to be carried out by

Since the tip of the robot arm can move in three dimensions and rotate on its own axis, it is necessary to drive the tool using a transmission means that does not pass through the tip of the robot arm. According to the invention, this transmission device is obtained in the following particularly advantageous manner. That is, the support supports an arm pivoting about the axis of the support, which arm has a belt transmission passing over two pulleys. The first pulley is coaxial with the pivot axis of the arm and the second pulley is at the tip of the arm. The arm is thereby coupled to the end of the flexible cable. The other end of the flexible cable is coupled to the tool holder head.

This coupling for motion transmission provides a large degree of freedom of movement for the end of the arm and the machining device supported on this end. Since the machining equipment must be capable of making approximately one complete revolution, the deflection of the pivoting transmission arm allows the tool holder to rotate approximately one complete revolution. At this time, the flexible transmission device should avoid collision with the arm or wrist of the robot. Advantageously, the machining device itself does not have to make a complete revolution, so it is expedient to limit the pivoting movement of the pivot arm about its axis with a stop.

According to another advantageous feature of the invention, the device has a relatively flexible second elongate member. One end of the elongate member is secured to a rigid support and the other end supports a weight. The elongate member also has a strain sensor connected to the control circuit. This allows the inertia of the machining device to be taken into account during the working movement.

This compensation measure is particularly useful when the machining equipment works rapidly, as is the case in the shoe manufacturing industry. actual,
It takes the machining equipment only 2-3 seconds to card one shoe.

According to another advantageous feature of the invention, the adjustable movable assembly is connected to the support by an I11 controlled double acting jack. This jack maintains the tool pressure at the reference pressure. In particular, this jack can be a pneumatic jack, allowing greater operating flexibility.

Advantageously, this double-acting pneumatic jack can be a so-called "frictionless" jack, which
It has two bellows operating on either side of the piston. This piston does not touch the cylinder wall.

[Example] Hereinafter, the machining fee of the present invention will be described in detail based on an example with reference to the accompanying drawings.

FIG. 1 is a front view of the machining apparatus of the present invention, and FIG. 2 is a side view thereof. In these figures, the machining equipment is
It is specifically intended to be fixed to the tip of a robot arm. The tip of the robot arm is shown schematically in the drawings. There is something called a "plate" at the tip of the robot arm, and there is a
It has 0 rotation degree of freedom. The mechanical unit that connects the tip of the arm to the plate is commonly referred to as the "wrist" (or sometimes referred to as the "head"). Tools such as gripping tools and welding tools are attached to this plate. These tools are connected to a power supply source by means of hoses, cables, etc.

In the case of FIG. 1, a machining device of the present invention is attached to a plate 1.

This machining tool U has a support 2. A portion 2a of the support 2 has fastening means (threaded holes 2a') to be fixed to the plate 1. The other part 2b of the support 2
is an extension of part 2a and supports the movable assembly described below.

The portion 2a also supports the motion transmission arm 3 and the arm 3
One end 38G of the part 2ak: is pivotally mounted. The other or free end 3b of the 7-arm 3 is connected to a motor or drive means 4 by a transmission 5, such as a flexible cable.

In practice, this transmission arm 3 includes a belt transmission. This belt transmission is formed by a pulley 6a coaxial to the pivot axis of the end 3a on the part 2a, a belt 6b and a pulley 6c arranged on the end 3b and connected to the transmission means 5. has been done.

Movement is therefore transmitted from end 3b to end 3a via belt 6b. At the end 3a, a pulley 6a supports a flexible transmission cable 7 coaxially therewith.

The pulley and cable are then fixed relative to each other against rotation. Cable 7 is coupled to and drives the movable assembly.

Part 2b supports a movable assembly consisting of a rigid arm 8, which is rigidly fixed to the end 9a of the deformable elongate member 9. The other end 9b of the elongated member 9 supports a tool holder head 11. The deformable elongated member 9 is fitted with a strain gauge sensor 10 and, if required, a swamp resistor.
to provide pin resistance). This strain gauge sensor 10 is for measuring the force exerted on the elongated member 9 in the direction of the double-headed arrow A. This force is caused by the component parallel to the arrow above of the various accelerations applied to the tool holder and tool body. In addition to these forces, the forces applied by the tool to the workpiece are vectorally modified.

Therefore, in FIG. 1, the actual direction of movement of the tool corresponds to the direction of movement of the tool holder 11, which is vertical. This movement is made possible by the flexibility of the elongated member 9 with which the rod 11 is fixed to the tool holder, even if only very slightly. This tool holder Rad 11 is the rotating part 1
1a, in which the shank of a tool, for example a cutter, is mounted. This part 11a is connected to the flexible cable 7 for the purpose of being rotationally driven.

The movable assembly also has position adjustment means consisting of a jack 12. The jack 12 is fixed to the part 2b of the support 2, and the piston 12a of the jack 12 is fixed to the rigid arm 8.

Therefore, due to the movement of the piston 12a within the jack 12, the movement of the rod 1 to the tool holder is controlled iQ,
The force applied to the workpiece by the tool is increased or decreased.

The two chambers 13', 13'' of the jack 12 are connected to fluid lines 14', 14''. These fluid lines connect to a fluid supply source 16 via proportionally acting distributors. This type of distributor includes a servo valve, a servo distributor, an electro-pneumatic converter, and is indicated by slide 15 in FIG. This slide 15 is connected to a fluid source 16 and a control tI! 1 device 17. Control device 17 receives information signals from strain gauge sensor 11 via signal line 18 .

According to an advantageous feature, the device according to the invention has a second flexible elongate member 20 . End 20 of this elongated member 20
a is connected to the rigid arm 8, and the other end 20b supports a weight. A strain gauge sensor 21 is likewise attached to this elongated member, and this strain gauge sensor 21 is connected to the control circuit 17 via a signal line 22.

This sensor 21 is an accelerometer, and its role is to measure an acceleration component in the direction of the double-headed arrow A. The circuit 17 makes it possible to calculate the inertial force on the tool holder and from this force to derive the actual force exerted by the tool on the workpiece. A further advantage of the device of the invention is that it provides what is called "rotational speed feedback" in servo-controlled AM systems.

Therefore, system stability and response time can be improved.

Generally speaking, the adjustment means or jack 12 is preferably a pneumatic jack and the fluid supply source 16 is preferably a source of compressed air. In particular, this pneumatic jack
It can be a jack with two deformable chambers 13', 13'' and is actuated from both sides of the member forming a floating piston without contact. The piston is connected to a connecting rod (not shown). coupled and guided in translation.

Generally, the pressure applied to the workpiece by the tool is a constant reference pressure. However, this pressure can also be varied according to a predetermined program along the path of the tool at the end of the robot arm. The circuit 17 is
It receives the result of measuring the actual pressure applied to the workpiece by the tool, and this signal is sent to the jack 1.
Used for control of 2. Then, the actual pressure is made equal to the reference pressure. If necessary, the signal from the second sensor 21 is taken into account.

The tool holder rod 11 is driven by the already mentioned transmission, which has on the one hand a flexible cable 7 by means of which the head 1
The rotating portion 11a of the transmission arm 3 is coupled to the shaft of the transmission arm 3. This axis is fixed relative to the end 1 of the robot arm. This transmission arm 3 is mounted so as to be pivotable about its pivot axis relative to the part 2a of the support 2. At that time, make sure that the movement of the robot arm is not obstructed.

Generally, the motor 4 is mounted at a fixed point. The output shaft of the motor 4 and the free end 3b of the transmission arm 3 are usually connected by a flexible and movable transmission cable.

Generally speaking, the tool holder rad 11 makes a pivoting movement along an arc. The center of movement is the connecting end 9a between the elongated member 9 and the rigid arm 8. This movement is
Once detected, it is compensated by a corresponding movement of the jack 12 acting on the arm 8. This sets the pressure applied by the tool to a reference value.

The machining equipment described above is simple to use.

This is because if the device is intended to machine parts with geometrically complex shapes, by manually guiding the tool along the machining path to be followed automatically, This is because it is sufficient to make the robot learn using the normal method. The robot then has the coordinates of this machining path stored in its computer and, if necessary, one reference pressure or several different reference pressures.

Once this machining path is entered into the storage device, the computer can automatically move the robot, thereby
The robot can perform work along a standard machining path and with a standard pressure.

Also shown in FIG. 1 are two stops 23, one on the left and one on the right. These stops limit the pivoting movement of arm 3 to t111. This makes arm 3 a complete 1
Rotation is not possible and does not interfere with the movement of the machining device and the end of the robot arm supporting it.

The side view of FIG. 2 shows some details of the pattern more clearly. In particular, this drawing shows the configuration of the transmission arm 3. The end of the transmission arm 3 (which is pivotable), which is fixed to the part 2a of the support 2, connects the rotating part 1 of the rod 11 to the tool holder by means of a flexible cable 7.
1a. A tool 24 in the form of a cutter is also shown in this figure. The double-headed arrow B shown at the jack 12 indicates the direction of movement of the movable assembly.

For clarity of the drawing, this figure does not show a side view of the rigid arm 8, the flexible elongated member 9, and the elongated member 21 to take into account the inertia of the movable assembly during rotation.

The invention described above is not limited to use attached to a robot arm.

The machining device can be stationary, or the workpiece can be moved over a tool mounted on a tool holder head. This is the case, for example, when an elongated product unwound from a supply reel is machined by moving it over a tool. For example, the product may be trimmed or machined on one or both edges and then re-rolled.

In this case, like when carding the upper of a shoe,
Even when the tool does not need to pass through a specific machining path,
It is important to keep the pressure applied by the tool constant. The device of the invention thus makes this possible.

[Effects of the Invention] As explained above, according to the present invention, the tool pressure is detected by the strain gauge sensor, and the tool holder head is moved through the movable assembly according to the detection result, so that the tool This has the advantage that the pressure can be made to match a predetermined reference pressure.

[Brief explanation of drawings]

FIG. 1 is a front view of the device of the present invention, and FIG. 2 is a side view of the device shown in FIG. 1... Tip of robot arm 2... Support body 8... Rigid arm 9... Flexible elongated member 10... Distortion Gauge sensor 11.11a... Tool holder head 12...
... Jacket 17 ... Control circuit 24 ... Tool

Claims (7)

[Claims] (1) A machining device specifically intended to be fixed to the tip of a robot arm, in particular with a cutter for carding operations in the shoe manufacturing industry or for clipping or polishing operations on parts of complex shape. In the apparatus, a tool holder head (11, 11a) for attaching a driven rotary tool (24), and a strain gauge sensor (10) for measuring the force exerted on the workpiece by the tool (24) are attached to the head ( 11, 11a
) is attached to a rigid arm (8) supporting a movable assembly (12) adjustable in the direction of actual movement of the tool (A, B).
, 8, 9, 20) with the rigid arm (8); and a movable assembly (12, 8, 9, 20) coupled to the tip (1) of the robot arm. 8, 9, 20); and a support body (2) that supports the strain gauge sensors (8, 9, 20); A control circuit (17) that controls the movement of the assembly
) A machining device characterized by having. (2) In the machining device according to claim 1, the means for driving the tool includes a motor (4);
This motor (4) is connected to the tool by a transmission, of which at least a part (7) of the part between the support (2) and the tool holder head (11, 11a) , a machining device characterized in that it is formed of a flexible cable for transmitting rotary motion. (3) In the machining device according to claim 2, the support (2) supports an arm (3), and the arm (3) pivots about the axis of the support. and includes a belt transmission (6b) passing over two pulleys (6a, 6c), the first pulley (6a) being connected to an arm (
The second pulley (6) is coaxial with the pivot axis of the second pulley (6).
c) is located at the tip of arm (3), and thus said arm (
3) is coupled to an end of a flexible cable (7), the other end of which is connected to said tool holder head (1).
1, 11a). (4) In the machining device according to claim 1, the machining device includes a device for measuring acceleration in the direction of the force applied by the tool ( 20), the acceleration comprising a destructive component of the weight of the movable assembly. (5) The machining device according to claim 1, wherein the movable assembly comprises a controlled double-acting jack (1
A machining device, characterized in that it is connected to said support (2) by 2), thereby making the pressure of the tool correspond to the reference pressure. (6) The machining apparatus according to claim 5, wherein the jack (12) is a pneumatic jack. (7) In the machining device according to any one of claims 1 to 3, the arm (3)
A machining device characterized in that it has two stops (23) for limiting the pivoting of the machine.