JPH0225548Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a feed length control device for an air feeder used when feeding a coil material or a fixed length object into a press machine or the like.

[Conventional technology]

As shown in FIGS. 8 and 9, for example, this type of air feeder is equipped with a fixed gripper 2 that clamps and unclamps the material at a fixed position on a frame 1, and a movable clamp 4 that is moved back and forth on a guide rod 3. The movable clamp 4 was reciprocated by an air cylinder (not shown) to move the material intermittently from the left side to the right side in the figure at a predetermined pitch.

In addition, in such conventional air feeders, it was difficult to stop the air cylinder midway, so for example, spacers 5, 5 were installed on the guide rod 3.
The air cylinder stroke (material feed length) was adjusted by attaching and detaching the air cylinder and changing its stroke end.

[Problem that the invention attempts to solve]

However, when changing the feed length by attaching and detaching the spacer in this way, it is necessary to remove the stroke adjustment screw 6 provided at the tip of the guide rod 3 and replace the spacers 5 and 5, so it is necessary to obtain the specified dimensions. Moreover, since the dimensions before and after adjustment cannot be recorded as numbers, it takes time for the next adjustment, or if the stroke adjustment screw 6 becomes loose during operation, the feed length may fluctuate. There was a problem with putting it away.

The present invention was developed to solve these conventional problems.It allows for one-touch adjustment, and has excellent adjustment workability and reliability since there is no possibility that the feed length will fluctuate during operation. The purpose of the present invention is to provide a feeding length adjusting device for an air feeder.

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a magnetic body inside the piston rod of an air cylinder that reciprocates a movable clamper that is paired with a fixed gripper provided at a predetermined position on the frame. The non-magnetic material portions are alternately formed at equal pitches. A primary coil to which a predetermined alternating current is applied and a secondary coil magnetically coupled to the primary coil are housed inside a sensor provided close to the piston rod. Further, a stroke detection means is provided for calculating the stroke of the air cylinder through the output of the secondary coil corresponding to the change in magnetic resistance accompanying the movement of the piston rod, and a stroke detection means is provided that calculates the stroke of the air cylinder through the output of the secondary coil corresponding to the change in magnetic resistance accompanying the movement of the piston rod. The present invention is characterized in that it includes a controller that stops the air cylinder when the detected actual stroke of the air cylinder coincides with the detected actual stroke of the air cylinder.

[Effect]

With this configuration, when the actual stroke of the air cylinder calculated based on the output of the secondary coil of the sensor installed close to the piston rod matches the preset value, the output from the controller The air cylinder is automatically stopped to maintain the feed length of the material at a predetermined value. . Furthermore, by changing the set value input as a digital value, for example, the air cylinder stroke (material feed length) can be arbitrarily changed within the maximum stroke range of the air cylinder. .

〔Example〕

Embodiments of the present invention will be described in detail below.

1 to 3 show the overall structure of an air feeder showing an embodiment of the present invention, and the upper surface of a frame 10 supported by a frame (not shown) indicates the feeding direction of the material (not shown). A sub-frame 12 is slidably mounted via a pair of guide rails 11, 11 extending in orthogonal directions, and a fixed gripper 13 is attached to one end of this sub-frame 12 (the right end in Fig. 1). .

Furthermore, a movable clamper 15 is slidably mounted on the upper surface of the sub-frame 12 via a pair of guide rails 14, 14 extending along the material feeding direction. Then, the frame 10 and subframe 1
2 through the air cylinder 16 along the guide rails 11, 11, and the subframe 1.
2 and the movable clamper 15 on the guide rails 14 and 1.
4, these air cylinders 16 and 17 can reciprocate the subframe 12 and the movable clamper 15 in predetermined directions, respectively. 18, 18, 19, 19 are guide rollers fixed to the upper surfaces of the fixed gripper 13 and the movable clamper 15, and these guide rollers 18, 1
8, 19, and 19 form a material transfer path.

Here, the control devices for both the air cylinders 16 and 17 are constructed as shown in FIGS. 4 to 6. In addition, since the control devices for both air cylinders 16 and 17 have the same configuration, here, the movable clamper 1
A control device for the air cylinder 17 that causes the air cylinder 5 to reciprocate will be explained.

That is, a sensor 20 and a brake 21 are provided at one end of the air cylinder 17, and magnetic parts 23 and non-magnetic parts 24 are formed alternately at equal pitches inside the piston rod 22 of the air cylinder 17. ing. Further, inside the sensor 20, which is slidably passed through the piston rod 22, there is a primary coil 25 to which a predetermined alternating current is applied from a power supply circuit (not shown), and a coil 25 wound around the outer circumference of the primary coil 25. A secondary coil 26 is provided (see Fig. 5).
An output terminal of this secondary coil 26 is connected to an input terminal of a stroke detection means 27.

On the other hand, the output (setting value) of the stroke setting means 28, which can manually set an arbitrary feed length with a digital value, and the output (detection value) of the stroke detection means 27 are sent to the controller 29 as control signals. At the same time, the brake 21 and the control valve 30 of the air cylinder 17 are connected to the output terminal of the controller 29. The brake 21 is constructed as shown in FIG. 6, and has air chambers 34 and 35 formed outside a pair of brake pistons 32 and 33, which are urged apart by a spring 31. The chambers 34, 35 and the air line are connected via a brake valve 36. . A disc spring 3 is provided between the outer surfaces of the brake pistons 32 and 33 and the split bushings 37 and 38 disposed on the outer side thereof.
By interposing the brake pistons 32 and 40, when air is supplied to the air chamber 41 formed between the brake pistons 32 and 33,
33 causes the split bushes 37 and 38 to contract in diameter via disc springs 39 and 40, thereby clamping and fixing the piston rod 22.

In an air feeder equipped with a control device having such a configuration, when the air cylinder 17 expands or contracts, the movable clamper 15 reciprocates in the left-right direction in FIG. As in the conventional method, by clamping and unclamping at predetermined timings, the material is fed from the left side to the right side in FIG. Furthermore, since the feed length of this material depends on the stroke of the air cylinder 17, the feed length can be changed by variably controlling the stroke of the air cylinder 17. Note that this is the same as the conventional one.

Here, in the present invention, Isinωt is applied to the primary coil 25 of the sensor 20 attached to the air cylinder 17.
The kneading machine is excited by applying an alternating current of Icosωt and Icosωt. Therefore, the piston rod 2 has magnetic parts 23 and non-magnetic parts 24 alternately formed at equal pitches.
2 moves and its magnetic resistance changes pitch by pitch, the voltage induced in the secondary coil 26 changes as the magnetic resistance changes, so the voltage induced in the secondary coil 26 changes. piston rod 2
Therefore, the amount of movement X of 2 can be detected.

That is, if the amount of movement of the piston rod 22 is The phase is shifted by an amount corresponding to the amount of movement X of 22. Therefore, if the phase difference between the two is digitally extracted using a converter or the like built into the stroke detection means, the amount of movement of the piston rod 22 can be detected as an absolute value within the range of one pitch of the magnetic body portion 23. be able to.
Furthermore, even if the amount of movement of the piston rod 22 becomes larger than one pitch, since the magnetic body portions 23 are continuously provided at equal pitches, the output voltage E of the secondary coil 26 will repeat the same change thereafter. By counting the pitches, the amount of movement of the piston rod 22 (actual stroke of the air cylinder 17) can be accurately detected.

Also, the air cylinder 1 detected in this way
A signal corresponding to the actual stroke of 7 is supplied to the controller 29 together with a signal corresponding to the target stroke set by the stroke setting means 28.

The controller 29 outputs a stop signal when the signal responsive to the actually detected stroke matches the signal corresponding to the target stroke, returns the control valve 30 to the neutral position (stops the movement signal), and controls the air cylinder. 17 and outputs an actuation signal to the brake valve 36.

When the actuation signal is supplied to the brake valve 36 in this way, air is supplied to the air chamber 41 formed between the brake pistons 32 and 33, and the air chambers 34 and 35 on both sides are released to the atmosphere. Ru. Then, both the brake pistons 32 and 33 move in the direction of separating from each other, and the disc springs 39 and 40
The piston rod 22 is clamped and fixed by the split bushes 37, 38 in order to reduce the diameter of the bushes 37, 38 via the pipe. Even if air is no longer supplied to the air chamber 41, the elastic force of the spring 31 will continue until air is supplied to the air chambers 34, 35 and the brake pistons 32, 3 are forcibly moved toward each other. Since the brake pistons 32 and 33 are held in separate positions, the piston rod 22 remains fixed.

Note that when the air cylinder 17 moves in the opposite direction to the above when the movable clamper 15 returns, the brake pistons 32 and 33 move in synchronization with this.
Since the inner air chamber 41 is released to the atmosphere and air is supplied to the outer air chambers 34 and 35, both brake pistons 32 and 33 move toward each other against the spring 31, thereby causing the disc springs 39 and 40
Since the diameter-reducing force exerted on the split bushings 37 and 38 is released, the restraining force on the piston rod 22 is released, and the movement of the piston rod 22 is allowed.

By displaying both the measured stroke value and the set stroke value of the air cylinder 17 as numerical values, etc., it is possible to easily confirm the adjusted value, and the next adjustment work can be carried out smoothly. It can be carried out.

In the embodiment, an air brake is used, but an electric brake may also be used.

Further, in the embodiment, the frame 10 and the fixed gripper 1
3 and the moving clamper 15.
2 and by reciprocating this sub-frame 12 in a direction perpendicular to the material transfer direction, the material can be cut in a zigzag manner as shown in FIG. 7, thereby increasing the yield of material cutting. However, it is not necessarily necessary to provide the subframe 12.

[Effect of idea]

As explained above, according to the present invention, the actual stroke of the air cylinder is detected by constantly monitoring the position of the piston rod, and when this detected value matches a preset arbitrary setting value, the air cylinder is forced to move. Since the air feeder is configured to be stopped automatically, the feed length of the air feeder can be easily and quickly adjusted without the troublesome work of attaching and detaching spacers as in the conventional case. In addition, since there is no need to use stroke adjustment screws, etc. as in the past, errors do not increase during operation.
The material can always be transferred with a stable stroke, thereby increasing the efficiency of adjusting the feed length of the air feeder and increasing the reliability of the air feeder.

[Brief explanation of drawings]

Fig. 1 is an overall plan view showing an embodiment of the present invention, Fig. 2 is a side view, Fig. 3 is a front view, Fig. 4 is a configuration diagram of the control device, and Fig. 5 is a cross section of the sensor. 6 is a sectional view of the brake, FIG. 7 is a plan view of the material cut out in a zigzag pattern, FIG. 8 is a plan view of the conventional example, and FIG. 9 is a front view. 10... Frame, 11... Guide rail, 1
2...Subframe, 13...Fixed gripper, 1
4... Guide rail, 15... Moving clamper, 1
6...Air cylinder, 17...Air cylinder, 1
8... Guide roller, 19... Guide roller, 2
0... Sensor, 21... Brake, 22... Piston rod, 23... Magnetic body part, 24... Non-magnetic body part, 25... Primary coil, 26... Secondary coil, 27... Stroke detection means , 28... Stroke setting means, 29... Controller, 30...
...Control valve, 31...Spring, 3
2... Brake piston, 33... Brake piston, 34... Air chamber, 35... Air chamber, 36...
...Brake valve, 37...Split bush, 3
8...Split bush, 39...Disc spring, 40...
...Disc spring, 41...Air chamber.

Claims (1)

[Scope of utility model registration request] a fixed gripper provided at a predetermined position on the frame;
In an air feeder equipped with a movable clamper reciprocally driven by an air cylinder, magnetic parts and non-magnetic parts are alternately formed at equal pitches in the piston rod of the air cylinder, and a predetermined alternating current is applied. A sensor including a primary coil and a secondary coil magnetically coupled to the primary coil is provided in close proximity to the piston rod, and the output of the secondary coil corresponds to a change in magnetic resistance due to movement of the piston rod. A controller that includes a stroke detection means for calculating the stroke of the air cylinder through the controller, and stops the air cylinder when a preset stroke and an actual stroke of the air cylinder detected through the stroke detection means match. An air feeder feed length control device comprising: