JPH0890109A - Work detector - Google Patents

Abstract

PURPOSE: To prolong the life of a work detector detecting a work held by a finger, and to prevent the occurrence of defective operation and malfunction. CONSTITUTION: The work detector is equipped with a casing 1 mounted on either of fingers 5a holding a work B, a rod 2 mounted slidably on the casing 1 and arranged so that whose tip 2a can come into contact with the work B when holding the work B by the fingers 5a and insulated electrically to the fingers 5a, and an energizing member 3 energizing the rod 2 in the direction of the work B. The rod 2 and the finger 5a are electrically connected through signal generating member 8b and power supply 8c, the possibility/impossibility of energizing in an electric circuit 8 is detected, and it is detected if the work is held by the finger.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work detector which is advantageous when applied to an apparatus for continuously working a work such as a transfer press.

[0002]

2. Description of the Related Art For example, in the field of press working, a plurality of molds may be arranged at a constant pitch, and these molds may be operated in synchronization with each other to perform different molding processes on a plurality of works at the same time. . In such a forming process, it is general to perform additional forming sequentially from the upstream side while transferring the work at a constant pitch, and a typical example is a transfer press device.

When a work is transferred at a fixed pitch, a device is used in which members called fingers are attached to a pair of feed bars that reciprocate at a fixed pitch. The fingers are composed of a pair of members arranged so as to face each other, and holding portions corresponding to the shape of the work are formed at the facing portions. When one press operation is completed, the formed work is held by the fingers and the feed bar is driven to transfer it to the downstream side, and the holding of the work by the fingers is released to place the work on the die on the downstream side. After the supply, the feed bar is moved to the upstream side so that the fingers return to their original positions and stand by.

The above-mentioned processing method has a problem that if the work cannot be reliably transferred to the mold of the next step, the mold may be destroyed by double-strike. Therefore, it is essential to detect whether or not the finger holds the work, and the following detection device is adopted.

The first detection device mechanically detects a work and generates an electric signal. A lot that is slidable and biased in the work direction is arranged on the finger, and the finger holds the work. At the same time, the work comes into contact with the lot and slides, and the dog formed in the lot actuates a micro switch in accordance with this slide, and an electric signal is generated by the switch to determine whether the work is held or not. It is detected (Japanese Utility Model Publication No. 56-95440).

The second detection device is for electrically detecting the work. The second detection device electrically insulates the finger and the feed bar, connects a power source to the pair of fingers, and holds the work by the fingers. The presence or absence of energization in the electric circuit formed by the work is detected to detect whether or not the work is held.

[0007]

SUMMARY OF THE INVENTION The above-mentioned first detection device has a problem that malfunction occurs and the life is short.
That is, the lot is worn and loosened by coming into contact with the work and sliding, and the dog formed in the lot cannot come into contact with the cam roller attached to the actuator of the microswitch, resulting in malfunction. The cam roller of the micro switch wears and cannot contact the dog of the lot, resulting in malfunction. The contact life of the micro switch is about 100,000 times,
In the case of pressing 4000 shots, there is a problem that the service life is reached in about 7 days and the replacement is required, resulting in high running cost.

In the second detection device described above, there is a high possibility that a malfunction will occur, and it will be necessary to take a long time for detection in order to prevent a malfunction, and there is a problem that it is not suitable for high-speed pressing. That is, when the work is held by the finger, the finger does not always hold the work firmly, and depending on the shape of the work, the work may be held by being placed on a part of the finger. In such a case, the power supply between the work and the fingers may be cut off due to vibration during transfer, and the work may be detected as being no work even though the fingers hold the work.

An object of the present invention is to provide a work detector which has a long life and is free from the risk of malfunction or malfunction.

[0010]

In order to solve the above-mentioned problems, a work detector according to the present invention comprises a casing attached to a finger for holding a work, and a slidable attachment to the casing and the work by the finger. A lot whose tip is arranged so as to come into contact with the work when held, and which is electrically insulated from the fingers, and a biasing member which biases the lot toward the holding part of the work at the fingers. And electrically connecting the lot and the finger and detecting the presence or absence of energization to detect whether or not the finger holds the work.

[0011]

In the above-mentioned work detector, the casing attached to the fingers is provided with a lot electrically insulated from the fingers, and the lot is arranged so that the lot can slide and the tip can come into contact with the work. Is urged in the direction of the work by the urging member, and the lot and the finger are electrically connected. Therefore, when the work is held by the finger, the tip of the lot comes into contact with the held work.

When the work is held by the fingers, the lot urged by the urging member presses the work even if there is looseness between the two. Therefore, an electric circuit including a lot, a work, and a finger is formed, and it is possible to detect the presence or absence of energization in the circuit. Therefore, by detecting the presence or absence of energization, it is possible to detect whether or not the work is held by the fingers.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the work detector will be described below with reference to the drawings. FIG. 1 is a perspective view illustrating the configuration of the work detector, FIG. 2 is a view illustrating a state in which the presence or absence of a work is detected by the work detector, and FIG. 3 is a view illustrating a usage mode of the work detector.

In the figure, a work detector A includes a box-shaped casing 1, a lot 2 slidably arranged in the casing 1 and having a tip contacting a work B, and a lot B containing a lot B.
It has a biasing member 3 that biases in the direction of.

The casing 1 is made of a metal box, and has holes 1b slidably supporting the lots 2 formed on both end faces 1a in the longitudinal direction. In addition, a plurality of holes 1c through which bolts for fixing the fingers 5a are inserted are formed in the bottom of the casing 1. The casing 1 does not necessarily have to be made of metal, and may be made of synthetic resin.

The lot 2 is made of a conductive material and is arranged so as to penetrate the casing 1. Further, at a position corresponding to the inside of the casing 1 of the lot 2, the lot 2 comes into contact with the inner surfaces on both sides of the casing 1.
A guide member 4 for guiding the moving direction of the lot 2 and preventing the rotation of the lot 2 is attached.

The urging member 3 is arranged inside the casing 1 and between the urging member 3 and the guide member 4 attached to the lot 2.
It has a function of urging the lot 2 toward the work B. As shown in FIG. 2, the biasing member 3 is provided at the tip 2 of the lot 2.
When a comes into contact with the work B, the work B is pressed in the direction of the opposing finger 5b (see FIG. 3) to prevent backlash of the work B, so that the work 5 is reliably held by the fingers 5a and 5b. It also has the function of In this embodiment, a compression coil spring is used as the biasing member 3.

The work detector A constructed as described above is
It is attached to one finger 5a of fingers 5a and 5b attached to a pair of feed bars 6a and 6b which are driven by a drive device (not shown) and reciprocate at a constant pitch. Further, the work detector A is connected to the finger 5a.
When attached to the lot 2, the lot 2 is electrically insulated from the fingers 5a.

Therefore, an insulating sheet 7 having an insulating property is arranged between the bottom surface of the casing 1 and the fingers 5a. Therefore, the finger 5a including the lot 1 as well as the casing 1 has an insulating property. However,
For example, when the casing 1 is made of an insulating synthetic resin, it is possible to insulate the lot 2 from the fingers 5a without interposing the insulating sheet 7.

Code 8 for lot 2 and fingers 5a
An electric circuit 8 including a signal generating member 8b and a power source 8c is connected via a. In this embodiment, since the casing 1 is made of metal, it is possible to connect the lot 2 and the power source 8c by connecting the cord 8a to the casing 1. However, when the casing 1 is made of synthetic resin, it is necessary to connect the cord 8c directly to the lot 2 or to attach a slip ring or the like to the lot 2 and connect the cord to the ring.

As described above, when the electric circuit 8 is simply connected to the lot 2 and the finger 5a, the circuit 8 is open and no current flows. However, as shown in FIG. 2, when the work B is held by the fingers 5a and 5b, the lot 2 comes into contact with the work B to close the electric circuit 8 and a current flows through the circuit 8. Therefore, the signal generating member 8b is excited to generate an electric signal, and it is possible to detect that the work B is held by the fingers 5a and 5b by the electric signal.

[0022]

As described above in detail, in the work detector according to the present invention, the electric circuit is closed by the contact with the work of the lot, and the fingers hold the work depending on the presence or absence of the current flowing in the circuit. It is possible to detect whether or not there is.

Since the above-mentioned lot is biased in the direction of the work by the biasing member, it is possible to prevent the backlash by pushing the work to one side, and a malfunction may occur due to vibration or the like generated when the work is transferred. It never happens. In addition, since the lot is supported so that it can slide back and forth in one direction with respect to the casing, and the work is detected electrically, the presence or absence of the work can be reliably detected if the lot is worn and the contact with the work is reliable. You can do it. Therefore, the life of the work detector can be extended, there is no time delay required for detecting the work, and the present invention can be applied to a press device driven at high speed.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating a configuration of a work detector.

FIG. 2 is a diagram illustrating a state in which the presence or absence of a work is detected by a work detector.

FIG. 3 is a diagram illustrating a usage mode of a work detector.

[Explanation of symbols] A work detector B work 1 casing 2 lot 3 biasing member 4 guide member 5a, 5b fingers 6a, 6b feed bar 7 insulating sheet 8 electric circuit 8b signal generating member 8c power supply

Claims (1)

[Claims] 1. A casing attached to a finger holding a work, and a casing slidably attached to the casing and arranged so that a tip of the finger can come into contact with the work when the work is held by the finger. An electrically insulated lot and an urging member that urges the lot in the direction of the work held by the finger, electrically connects the lot and the finger, and detects the presence or absence of energization. A work detector characterized by detecting whether or not a finger holds a work.