JPH0338936B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides an automatic punch changer installed in a cold heading machine for forming screw heads.
The present invention relates to a device that performs correction control to stop a punch holder at a predetermined position suitable for automatic exchange.

(Prior Art) A known cold heading machine A for screws has a configuration as shown in the plan view shown in FIG. The work is automated so that it is performed continuously. In this cold heading machine A, when the punch wears out or breaks during operation, it is necessary to immediately stop the machine and replace the punch attached to the punch holder 7. In order to achieve unmanned operation at night, etc., it is desirable to automatically replace punches without relying on humans.

Such an automatic punch changing device B has already been proposed by the present applicant in Japanese Patent Laid-Open No. 162545/1983.

The device B is installed on the upper part of the cold heading machine A for screws, and as shown in FIGS. 7 to 9, it has a first forming punch 31 for rough forming the screw head and a second forming punch 31 for finishing This device automatically replaces the second forming punch 32, which is particularly prone to breakage and is frequently replaced, of the double stroke cold header consisting of the forming punch 32. This allows the forming punch to be attached to and removed from the punch holder. The structure for this purpose includes a fixed position stopping device (not shown but described later) that stops the horizontal ram 10 with the punch holder 7 of each punch attached at a predetermined position suitable for punch replacement, and a fixed position stopping device (not shown but described later) that stops the horizontal ram 10 on which the punch holder 7 of each punch is attached. The first gripping device 34 inserts and removes the locking pin 33 for locking the holder 7, and the old second forming punch is removed and discarded, and a new second forming punch is removed from the storage area for the replacement second forming punch. A second step for taking out the forming punch and mounting it on the punch holder 7.
a gripping device 35, said fixed position stop device and a first
and a control device for operating the second gripping device. The fixed position stop device stops the material feeding device of the cold heading machine main body in response to a stop signal from the control device, and also turns off the power of the main motor of the main body so that the main motor rotates at a preset rotation speed. After the vehicle has been decelerated to a certain point, the vehicle is stopped at a desired fixed position by either operating the brake device, or switching to the low-speed motor via a cam clutch, etc., and then operating the brake device.

(Problems to be Solved by the Invention) In the conventional fixed position stopping device described above,
Accidents have occurred in which automatic punch replacement work has become impossible due to variations in the stopping position due to motor inertia and timing delays during power transmission by the clutch.

Therefore, the present invention improves these problems and
It is an object of the present invention to provide a fixed position correction control device that can reliably perform automatic exchange of punches by performing supplementary control of the stop position to improve accuracy.

(Means for Solving Problems) The gist of the present invention is to stop the main motor of a cold heading machine for screws, and engage the power transmission mechanism such as the flywheel, which is almost stopped, with the geared motor. At the same time, a detector installed adjacent to the material feed plate equipped with a positioning terminal detects whether or not the punch holder attached to the horizontal ram is at the desired exchange position. The purpose is to stop the motor and correct the punch replacement position.

(Example) Examples of the present invention will be described below based on the drawings. The fixed position correction control device is configured as shown in FIG. 1 so that the punches (in particular, the second forming punch 32) can be replaced by the first gripping device 34 and the second gripping device 35 in the automatic punch changing device A described above. The punch holder 7 attached to the horizontal ram 10 is stopped accurately at the desired exchange position T, and the detection unit detects whether or not the punch holder 7 is at the exchange position T.
_C1 , a drive unit _C2 that drives the drive unit to the relevant position, and a control unit _C3 that controls these.

This fixed position correction control device is closely related to the power transmission mechanism portion of the cold heading machine A shown in FIG. 6, and FIG. 11 is a plan view showing the relationship between the two. First, the cold heading machine uses a main motor (not shown)
A crankshaft 12 is attached to a flywheel 11 which is interlocked with the crankshaft 11, and reciprocates a horizontal ram 10 via a connecting rod 14.

The flywheel 11 has a large diameter gear 1 for low speed.
01 is integrally attached to this low speed large diameter gear 10.
A geared motor 103 equipped with a small-diameter gear 102 meshing with the motor 1 is disposed so as to be able to approach and separate as shown in FIGS. 3 and 4. Said geared motor 10
3 is mounted on a movable plate 107 whose one end is pivotally supported by a base plate 105 via a support rod 104 and is swingable, and whose other end is connected to a piston rod of a cylinder 106 to extend the piston rod of the cylinder 106. As a result, the other end of the movable plate 107 is raised to the same height as the one end, and at this time, the small diameter gear 102 of the geared motor 103 meshes with the low speed large diameter gear 101 attached to the flywheel 11. The above is the configuration of the drive section _C2 in the fixed position correction control device.

Next, the pinion 16 mounted on the crankshaft 12 meshes with the cam gear 15 mounted on the subshaft 23 at a tooth ratio of 1:2, and the material feed plate 24 is mounted on the subshaft 23. A position detection terminal 112 made of a magnetic material or the like is provided. Further, in order to detect the presence of the position detection terminal 112 and give a stop command to the geared motor 103, a first detector 11 equipped with a proximity sensor such as a proximity switch is installed adjacent to the material feed plate 24.
The detection section _C1 is configured by arranging the detector C1 and the second detector 111 as shown in FIG.

Next, the control section _C3 for controlling the above-mentioned detection section _C1 and drive section _C2 is constructed by a combination of known circuits so as to operate as shown in the float chart shown in FIG.

To explain its operation below, first, the main motor driving the cold heading machine A is stopped, and its inertia operation initializes each part via the power transmission mechanism shown in Fig. 1, such as the flywheel 11. Bring it to a natural stop near stop position 5. Next, the cylinder 106 provided in the drive unit C ₂ is extended by a timer set in advance to predict the natural stop time, and the small diameter gear 102 of the geared motor 103 is set to the low speed of the flywheel 11. The flywheel 11 is engaged with the large-diameter gear 101 to rotate the flywheel 11 at a low speed. When the flywheel 11 rotates, the crankshaft 12 and conrod 14
The punch holder 7 attached to the horizontal ram 10 is moved toward the exchange position T via the
The material feed plate 24 rotates via the pinion 16, cam gear 15, etc., at a speed that is further reduced to one half of the rotation of the flywheel 11. When the punch holder 7 reaches the desired exchange position T during the low-speed rotation of the material feed plate 24, the positioning terminal 112 attached to the material feed plate 24 is connected to the first detector 11.
0 and the second detector 111, and both detectors 110 and 111 are turned on to give a command to stop the rotation of the geared motor 103.

In this case, by operating both the first detector 110 and the second detector 111, the punch holder 7 is stopped within the range of the desired exchange position T, and the punch holder 7 is stopped at another position, for example, immediately before the first detector _110. The geared motor 103 does not stop at _S2 immediately after passing the second detector 111. Therefore, detection accuracy is improved, and even if the initial stop position at which the main motor naturally stops after inertia operation is at _S1 or _S2 , accurate correction can be performed.

In the above-described embodiment, a large-diameter low-speed gear is provided on the flywheel, but depending on the structure of the cold heading machine for screws, a large-diameter low-speed gear may be provided on other power transmission mechanisms such as pulleys. Also good. Further, the same effect can be obtained by providing the position detection terminal not on the material feeding plate but on the material cutting adjusting plate which is pivoted on the same subshaft and disposing the detector adjacent thereto. Furthermore, within the scope of the gist, such as using a rotary encoder or other detector instead of a proximity sensor as a detector, or engaging the small diameter gear of the geared motor with the large diameter gear for low speed immediately before stopping the inertial operation. Various modifications are possible.

(Effects of the Invention) As is clear from the embodiments described above, the fixed position correction control device according to the present invention provides the following effects.

First, since correction control is automatically performed when the initial stop position of the punch holder is not at the desired replacement position, the accuracy is significantly improved compared to the conventional technique in which the punch holder is stopped by braking during low-speed operation. In particular, the use of meshing drive using gears prevents interference and positional displacement due to inertia. Furthermore, an embodiment in which two detectors are provided and the geared motor is stopped by the AND output of the detectors further improves the accuracy of the stopping position.

[Brief explanation of the drawing]

FIG. 1 is an overall diagram showing an outline of the fixed position correction control device according to the present invention, FIG. 2 is an explanatory diagram of the detection section of the device, FIGS. Figure 5 is a flowchart of the control section of the device.
FIG. 6 is an overall plan view showing a cold heading machine for screws, FIG. 7 is a schematic explanatory view of an automatic punch exchange device, and FIGS. 8 and 9 are explanatory views of essential parts of the device. [Explanation of symbols], 7...Punch holder, 10
...Horizontal ram, 11...Flywheel, 12...
...Crankshaft, 14...Conn rod, 15
... Cam gear, 16 ... Pinion, 23 ... Subshaft, 24 ... Material feeding plate, 101 ... Large diameter gear for low speed, 102 ... Small diameter gear, 103 ...
Geared motor, 104...branch, 105...base plate, 106...cylinder, 107...
Movable plate, 108...Mounting bracket, 11
0...First detector, 111...Second detector, 11
2...Positioning terminal, A...Cold heading machine for screws,
B... Automatic punch exchange device, C ₁ ... Detection unit, C ₂
...Drive section, C ₃ ...Control section, T...Replacement position.

Claims (1)

[Claims] 1. In order to automatically exchange the punch attached to the punch holder of a cold heading machine for screws, the punch holder attached to the tip of the horizontal ram is stopped at a predetermined exchange position where an exchange device waits. A drive unit that stops the horizontal ram in continuous high-speed operation and switches it to low-speed operation during inertia operation, and whether or not the punch holder is in the desired exchange position during this low-speed operation. The drive unit consists of a detection unit that detects the noise, and a control unit that controls these.The drive unit connects a large-diameter low-speed gear to a power transmission mechanism such as a flywheel or pulley connected to a crankshaft that drives a horizontal ram. In addition, a geared motor equipped with a small-diameter gear is disposed adjacent to this large-diameter gear for low speed so as to be able to come into contact with and separate from it, and the detection section is connected to a material feeding plate or material cutting adjustment that is rotated in conjunction with a gear down from the crankshaft. A positioning terminal is provided on the plate, and two adjacent detectors are provided along the rotation path of the material feed plate or material cutting adjustment plate, and the control unit stops and operates the main motor of the cold heading machine for screws. After a predetermined period of time, the drive section is controlled so that the small diameter gear of the geared motor is engaged with the large diameter gear for low speed to operate the horizontal ram at a low speed, and a positioning terminal is connected between both detectors of the detection section. Immediately after the first detector detects the positioning terminal, the second detector detects the positioning terminal and operates simultaneously, and a stop instruction is given to the geared motor based on the signals from both detectors. Characteristic fixed position correction control device.