JP2000153317A - Plate stock machine driving system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plate stock machine driving system provided with a highly safe piston operational position detecting mechanism capable of preventing a base plate connected to a piston of a ram cylinder or the like from being affected by distortion and maintaining/improving machining precision. SOLUTION: In the piston operational position detecting mechanism K being the driving system for plate stock machine P and detecting the operational position of a piston reciprocating in a ram cylinder 1, a pair of differential transformers 3 are loosely fitted externally, a vertically movable bar-like iron core part 4 is connected integrally to a pillar-like member 5 served as a detent for the piston and paired with a top dead center proximity switch 7 for the piston, a base part of the pillar-like member 5 served both as a function of a receiving part for the top dead center proximity switch 7 and a function as the detent for the piston is vertically attached to the tip end part of a base plate 6 orthogonal to the piston rod 2 and projectingly provided in the horizontal direction at the tip end of the piston rod 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a driving system for a plate processing machine such as a turret punch press.

[0002]

2. Description of the Related Art In a plate material processing machine of a hydraulic drive system type equipped with an NC control device such as a punching process and a forming process,
A dog which serves as a base of a rod-shaped core portion for detecting the operating position of the piston of the hydraulic cylinder in pair with the differential transformer, and a detent (also serving as a detent for the piston which is paired with the top dead center proximity switch of the piston) In general, the bases of the columnar members provided with a dog) are separately mounted vertically at two positions of a base plate front end protruding horizontally at the front end of the piston rod.

[0003]

However, in the above-mentioned conventional example, the rod-shaped iron core paired with the differential transformer and the dog / piston rotation preventing columnar member paired with the piston top dead center proximity switch are used. Since the base plate connected to the piston rod is vertically mounted separately at two places, the base plate connected to the vertically moving piston rod by projecting in the horizontal direction at right angles to the piston rod may be warped. When distortion occurs (see FIG. 3), there is a problem in that the accuracy of detecting the operating position of the piston is reduced, which affects the accuracy of punching and forming.

The present invention has been made by paying attention to the above-mentioned points, and prevents or eliminates the influence of warpage or other distortion generated on a base plate connected to a piston of a ram cylinder, thereby reducing the processing accuracy. It is an object of the present invention to provide a drive system for a sheet material processing machine provided with a highly safe piston operation position detection mechanism that enables maintenance and improvement.

[0005]

The present invention can solve the above-mentioned problems by providing the following constitution.

(1) In a drive system for a plate processing machine such as a turret punch press, in a piston operating position detecting mechanism for detecting an operating position of a piston, a differential transformer is externally fitted loosely to form a pair. A vertically movable rod-shaped core portion is connected to a columnar member serving as a detent for the piston to form an integral body, and is paired with a top dead center proximity switch serving as a sensor for detecting the top dead center of the piston. The base of the columnar member, which also has a function as a receiving part of the top dead center proximity switch and a function to prevent rotation of the piston, is protruded from the tip of the piston rod in the horizontal direction orthogonal to the piston rod. A drive system for a plate material processing machine, comprising a piston operating position detecting mechanism vertically attached to a tip of a base plate provided.

(2) The rod-shaped core portion has a stepped structure having a large diameter portion and a small diameter portion, an appropriate length portion that moves up and down in the differential transformer is a small diameter portion, and the small diameter portion is cylindrical elastic. The small diameter portion has the same diameter as the large diameter portion by being covered with the body, and has a minute gap between the small diameter portion and the outer edge when fitted to the top of the small diameter portion, and the outer diameter is equal to the large diameter portion. The above-mentioned (1), wherein the same desired small cylindrical member is interposed and screwed from above with a fixing screw to form a flexible structure as a whole.
The drive system of the plate processing machine according to the above.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below.

FIG. 1 (a) is a partially cutaway side view showing an embodiment of the present invention, FIG. 1 (b) is a longitudinal sectional side view showing the configuration of a rod-shaped core in another embodiment, and FIG. FIG. 3 is an explanatory view showing a configuration example including a feedback control type hydraulic servo circuit, FIG. 3 is a schematic side view showing a conventional configuration example, and FIG. 4 is a front view of a turret punch press as an example of a plate processing machine.

In the present embodiment, the operating position of the piston during the operation such as punching or forming by the action of a hydraulic cylinder / piston in a plate processing machine such as a turret punch press employing an NC control hydraulic drive system is determined. An example in which feedback control is performed by a hydraulic servo circuit having a servo valve, which is detected by a transformer, will be described.

First, a turret punch press employing the present invention will be described with reference to FIG. 4. An upper turret equipped with a large number of punches and a lower turret equipped with a die corresponding to the punch under the upper frame are provided with a lower turret. Each punch is provided rotatably on the frame, and a desired punch / die is positioned directly below the ram cylinder 1 provided at the center of the upper frame by the rotation of the upper and lower turrets.

Further, the carriage, to which the clamp C holding the workpiece W is attached, is moved on the carriage base by a motor ball screw (not shown) on the X axis (perpendicular to the plane of FIG. 4).
By moving the carriage base in the Y-axis direction (left and right in FIG. 4) using a motor ball screw,
A desired processing position on the work W is positioned between the punch and the die immediately below the ram cylinder 1, and the work such as punching and forming is performed on the work W by the operation of the ram cylinder 1.

Next, the piston operating position detecting device of the ram cylinder 1 which is a main part of the present invention will be described with reference to FIGS. The columnar member 5 is vertically attached to the tip of the provided base plate 6. The columnar member 5 is guided by a bracket 7a provided on the outer wall of the ram cylinder 1 when moving up and down, and performs a function of preventing the rotation of the piston. A top dead center proximity switch 7 is provided on the bracket 7a, and when the piston of the ram cylinder 1 is at the top dead center,
The upper end of the columnar member 5 also functions as a dog, and is detected by the top dead center proximity switch 7.

A rod-shaped iron core 4 is vertically mounted on the upper end of a columnar member 5, and the rod-shaped iron core 4 is provided in an operation transformer 3 provided with a coil 3a on the outer wall of the ram cylinder 1 via a bracket 3b. It can be moved up and down.

The operation will be described based on the above configuration.

A work W gripped and moved and positioned by a work clamp C of a turret punch press as an example of the plate material processing machine P, and inserted between predetermined punches and dies,
A machining operation is started by a command from the NC control device, and the piston rod 2 in the ram cylinder 1 is operated for a predetermined stroke, thereby performing product machining. At this time, following the operation of the piston rod 2, the tip of the piston rod 2
A base plate 6 projecting in a horizontal direction perpendicular to the piston rod 2 causes displacement, and this base plate 6
The columnar member 5 which is vertically mounted on the tip end of the rod-shaped member and integrated with the rod-shaped core portion 4 follows the displacement, and is externally fitted to the rod-shaped core portion 4 which can move up and down in accordance with the displacement. A differential transformer 3 provided with a coil 3a which is loosely mounted and which is a component of a piston operation position detecting mechanism detects a displacement of the rod-shaped core portion 4, and transmits the detected value to an NC control device.
Based on a command from the NC control device, feedback control is performed on a hydraulic servo circuit that has a servo valve and controls a hydraulic pump that is operated by a motor drive, thereby performing high-precision machining.

Further, as another embodiment, the bar-shaped iron core portion 4 has a stepped structure having a large diameter portion and a small diameter portion, and an appropriate length portion which moves up and down in the differential transformer 3 is a small diameter portion 8. The small-diameter portion 8 is covered with a cylindrical elastic body 9 to form a large-diameter portion 1.
0, has a small gap (clearance) between the top of the small diameter portion 8 and the outer edge of the small diameter portion 8 when fitted to the small diameter portion 8, and the outer diameter is large. A desired small cylindrical member 11 which is the same as the part 10 is interposed and screwed with a fixing screw 12 from above to form a flexible structure as a whole,
The flexibility of the cylindrical elastic body 9 and the playability of the small cylindrical member 11 prevent damage to the bar-shaped core portion 4 when distortion occurs in the base plate 6 or an engaging portion, Absorbs or eliminates the effects of the distortion and prevents it,
It is possible to maintain and improve the accuracy of detecting the piston operating position.

Further, an upper dead center proximity switch 7 is provided to sense the top dead center of the piston via the columnar member 5 which has a function of a dog and a function of preventing the piston rod 2 from rotating. Is properly regulated.

As described above, the rod-shaped core 4 and the columnar member 5 are united and integrated, and the point of support to the base plate 6 is set to one point. The effect of the distortion of the base plate 6, which is a drawback of being separately supported at two points, is eliminated, and the processing accuracy can be maintained and improved. Further, as another embodiment, the rod-shaped core 4 is made of a flexible cylindrical member. By using a small cylindrical member 11 having a loose fit function as a slider and covered with the elastic body 9 to absorb or eliminate the influence of distortion and prevent damage, further safety is provided. This makes it possible to provide a piston operating position detecting mechanism having a characteristic.

[0020]

According to the present invention, the safety of absorbing and eliminating the effects of warpage and other distortions generated on the base plate connected to the piston of the ram cylinder and maintaining and improving the processing accuracy is achieved. And a piston operating position detecting mechanism having a high operating speed can be provided.

[Brief description of the drawings]

FIG. 1 (a) is a partially cutaway side view showing one embodiment of the present invention, and FIG. 1 (b) is a longitudinal sectional side view showing the configuration of a bar-shaped core in another example.

FIG. 2 is an explanatory diagram showing a configuration example including a feedback control type hydraulic servo circuit.

FIG. 3 is a schematic side view showing a conventional configuration example.

FIG. 4 is a front view of a turret punch press as an example of a plate processing machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ram cylinder 2 Piston rod 3 Differential transformer 3a Coil 3b Bracket 4 Bar-shaped iron core part 5 Column member 5a Bush (cylindrical member with flange) 5b Screw part 6 Base plate 7 Top dead center proximity switch 7a Bracket 8 Small diameter part 9 Cylindrical elastic body Reference Signs List 10 Large-diameter portion 11 Small cylindrical member 12 Fixing screw C Work clamp K Piston operation position detecting mechanism P Plate processing machine W Work

Claims (2)

[Claims] 1. A driving system for a plate material processing machine such as a turret punch press, wherein a piston operating position detecting mechanism for detecting an operating position of a piston is formed by externally fitting a differential transformer to form a pair. A vertically movable rod-shaped core is connected to a columnar member that serves as a detent for the piston to form an integral unit, and a pair is formed with a top dead center proximity switch that serves as a sensor for sensing the top dead center of the piston. The base of the columnar member, which also has a function as a receiving portion of this top dead center proximity switch and a function to prevent rotation of the piston, is provided at the tip of the piston rod so as to protrude in a horizontal direction orthogonal to the piston rod. A drive system for a plate processing machine, comprising a piston operating position detecting mechanism vertically mounted on a tip end of a base plate. 2. The bar-shaped core portion has a stepped structure having a large-diameter portion and a small-diameter portion. An appropriate length portion that moves up and down in the differential transformer is a small-diameter portion, and the small-diameter portion is a cylindrical elastic body. To form the same diameter as the large diameter portion, and when fitted to the top of the small diameter portion, has a minute gap with the outer edge of the small diameter portion, and the outer diameter is the same as the large diameter portion. The drive system for a plate processing machine according to claim 1, wherein a desired small cylindrical member is interposed and screwed with a fixing screw from above to form a flexible structure as a whole.