JP4367343B2 - Work holding device - Google Patents

Description

  The present invention relates to a workpiece holding device capable of detecting that a workpiece is held in a normal posture.

When the ring-shaped valve insert (V / I) is press-fitted into the intake / exhaust hole of the engine cylinder head, a press-fitting device that press-fits the valve insert is used. In the press-fitting device, for example, a work such as the valve insert is held by a spring-type plunger installed on a press-fitting head provided in the press-fitting device to perform a press-fitting operation. By the way, the valve insert has a curved surface shape in which one surface is flat and the other surface abuts against the valve head portion, and the front and back surfaces are asymmetric surfaces. For this reason, when holding such an asymmetrical workpiece on the press-fitting head, it is necessary to hold the workpiece in a normal posture. However, the press-fit head as described above can hold the workpiece even when the front and back sides are different, and the press-fit operation is performed with the workpiece in the opposite posture, which may damage the receiving side of the cylinder head or the like. There is. In addition, since it is not detected whether or not the workpiece is held at an appropriate holding position, when the workpiece is dropped during the press-fitting operation, the workpiece flows to the subsequent process without being press-fitted.
For such a problem, a press-fitting head that can determine the front and back of the workpiece to be held has been proposed (for example, see Patent Document 1). In this press-fitting head, front / back determination is performed by detecting the movement position of the spindle that moves when holding the workpiece.
JP-A-5-253759

  However, even with a press-fitting device having a front / back determination function as described above, it is difficult to detect when the workpiece is not held by the head or when the workpiece is dropped after being held, and the above-described problems still remain. Remains.

  The present invention has been made against the background of the above circumstances, and is capable of accurately detecting whether or not a workpiece is dropped by continuously detecting whether or not the workpiece is properly held. An object is to provide an apparatus.

That is, among the workpiece holding devices of the present invention, the invention according to claim 1 has a workpiece holding head for holding the workpiece, and the workpiece holding head accepts holding of the workpiece corresponding to the normal holding of the workpiece. And a detection member that slides as the workpiece is held and is opened and closed as the detection member slides, and the detection member is not slid And a normal holding detecting means for detecting whether the normal holding of the workpiece is normal or not by a ventilation operation of air through the air discharging port. The air discharge port is closed in a state where the workpiece is slid in accordance with holding acceptance and the workpiece is not properly held, and the air discharge port is opened in a state of sliding in accordance with the normal holding of the workpiece. The And butterflies.

  Next, the workpiece holding device according to claim 2 is characterized in that, in the invention according to claim 1, the workpiece holding head has a restriction-shaped portion that regulates irregular holding acceptance of the workpiece.

The work holding device according to claim 3 is characterized in that, in the invention according to claim 1 or 2 , sliding is restricted in a state where the work is normally held .

The work holding device according to claim 4 is the invention according to any one of claims 1 to 3 , wherein the detection member communicates with the air discharge port in a state where the work is normally held by the sliding. In addition, an exhaust port that does not communicate with the air exhaust port when the work is not properly held is provided.

That is, according to the present invention, the workpiece is held and received in a normal posture by the receiving shape portion. The detection member that moves as the workpiece is held and received becomes a means for continuously detecting whether or not the workpiece is normally held by the normal holding detection means. As a result, normal acceptance of the workpiece is detected, and whether or not the workpiece is in a regular holding state is detected, and it is possible to detect when the workpiece is not held or when it is dropped after being held.
It is desirable that the holding head has a restriction-shaped part that restricts the work from being held and received in an irregular posture. As a result, the workpiece can be prevented from being held and accepted in an irregular state.

The detection means is for moving him to receive and retain the workpiece, that make up the member to slide relative to the holding head. For example, it can be configured by a dog ring loosely fitted to the holding head.

Regular holding detecting means is adapted to allow continuously detects the movement of the sensing means, the air outlet is configured to be opened and closed in accordance with the movement of said sensing means, Ya flow of air by opening and closing operation By measuring the pressure, it is possible to detect whether or not the workpiece is in the normal holding position.

  The workpieces that can be used in this apparatus may be any one that has a different shape in terms of the workpiece. For example, valve inserts with different front and back surfaces can be representatively exemplified. The shape of the holding head that holds the workpiece is determined according to the shape of the workpiece. For example, when holding a ring-shaped workpiece, the holding head is configured in a shape for inserting and holding the workpiece.

According to the present invention, it has a work holding head for holding a work, and the work holding head has a receiving shape portion that enables holding and receiving of the work corresponding to normal holding of the work, A detection member that slides as the workpiece is held , and an air discharge port that is opened and closed as the detection member slides and is open when the detection member is not slid. A normal holding detecting means for detecting whether the normal holding of the workpiece is normal or not by an air ventilation operation through an air discharge port, and the detection member slides as the holding of the workpiece is received, and the workpiece is properly said air outlet in a state of not being held closed, since the air discharge port opens in a state of being slid in response to the regular holding of the workpiece, the shape of the holding head regular acceptance of the work It can be easily performed, and it is continuously detected whether or not the workpiece is held at the normal position. In addition to detecting the normal holding at the time of holding, whether or not the workpiece is held normally is detected. It is also possible to accurately detect the dropout of. Therefore, even when performing work for press-fitting the held work to the receiving side, the work is not press-fitted in a non-regular posture, and it is also possible to prevent the work from flowing into a subsequent process without being press-fitted. it can.

(Embodiment 1)
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
The workpiece 1 to be held has a ring shape and a tapered shape whose inner peripheral surface changes in diameter from one end side to the other end side. In this work 1, the inner diameter large diameter side becomes the regular receiving surface 1a for the work holding device, and the inner diameter small diameter side becomes the non-regular surface 1b.
A workpiece press-fitting device corresponding to a workpiece holding device includes a workpiece press-fitting head 2 corresponding to a workpiece holding head, and the workpiece press-fitting head 2 is attached to the tip of a head mounting rod 3.
As shown in detail in FIG. 2, the workpiece press-fitting head 2 has a small diameter introduction cylinder portion 20 into which the workpiece 1 can be inserted at the tip portion, and an introduction portion 20 a formed with a tapered surface is provided at the tip portion. It has been. A workpiece receiving surface 20b that is a workpiece receiving shape portion is formed on the rear side of the introduction cylinder portion 20 with a tapered surface that gradually increases in diameter toward the rear so as to follow the inner surface of the workpiece 1. At the rear end of the workpiece receiving surface 20b, there is provided a workpiece abutting wall portion 21 with which the regular workpiece receiving surface 1a can abut. When the workpiece is properly received, the workpiece contact wall portion 21 regulates the movement of the workpiece and regulates the sliding of the detection member described later. The introduction cylinder portion 20 is provided with three ball plunger installation holes 22 at intervals of 120 degrees. Further, the workpiece press-fitting head 2 is formed with sliding grooves 23... 23 penetrating back and forth at intervals of 120 degrees between the ball plunger mounting holes 22 and 22. A mounting bolt 24 protrudes from the rear end of the work press-fitting head 2 and can be attached to the head mounting rod 3 described above.

  As shown in detail in FIG. 3, the head mounting rod 3 is formed with a mounting bolt hole 30 into which the mounting bolt 24 is screwed. A vent passage 31 is formed in the head mounting rod 3 so as to penetrate rearward in the axial center, and the front end penetrates the mounting bolt hole 30. The ventilation path 31 is configured such that the front end side is sealed by screwing the mounting bolt 24 into the mounting bolt hole 30. A part of the front side of the air passage 31 is open to the outer peripheral wall of the head mounting rod 3, and the opening constitutes an air discharge port 32 that forms part of the regular holding detection means. An air intake port 33 connected to an air supply source (such as factory air) (not shown) is formed at the rear end of the air flow channel 31, and the air flow channel 31 branches in the vicinity of the air intake port 33. The head mounting rod 3 is open to the outer peripheral wall. The opening is assigned to the air pressure detection hole 34, and an air pressure measuring device (not shown) is airtightly attached to the air pressure detection hole 34.

  Further, the distal end side of the head mounting rod 3 is formed in multiple stages so as to increase in diameter toward the rear, and the small diameter portion on the distal end side becomes a sliding cylinder portion 35 into which a detection member described later is loosely fitted. ing. Further, a coil spring 40 is loosely fitted as an urging member on the outer periphery of the sliding cylinder portion 35 and the rear middle diameter portion 36, and there is a step between the middle diameter portion 36 and the rear larger diameter portion. It is a support surface at one end of the coil spring.

After the coil spring 40 is fitted into the head mounting rod 3, the dog ring 41 corresponding to the detection member of the present invention is loosely fitted to the head mounting rod 3 in front of the coil spring 40. The dog ring 41 has a cylindrical portion 42, and three extending pieces 43 extend forward from the distal end side of the cylindrical portion 42 at the same diameter as the cylindrical portion 42 at intervals of 120 degrees (see FIG. 4). .
Further, on the rear side of the cylindrical portion 42, a cylindrical portion having the same inner diameter as the cylindrical portion 42 and a small outer diameter is continuous, and the cylindrical portion constitutes an air discharge control cylindrical portion 44. An exhaust port 45 is provided on the rear side of the air discharge control cylinder portion 44 as shown in FIG. 6 (omitted in other drawings).
The inner diameter of the dog ring 41 is set to be slightly larger than the sliding cylinder portion 35 and smaller than the middle diameter portion 36. Thereby, the dog ring 41 can slide on the sliding cylinder portion 35.
In the head mounting rod 3, after the coil spring 40 is fitted, the dog ring 41 is loosely fitted so that the elongated piece 43 is in front. Thereafter, the press-fitting head 2 is attached and fixed to the head mounting rod 3 so that the elongated pieces 43 are positioned in the sliding grooves 23, respectively. In the press-fitting head 2, ball plungers 25 are installed in the ball plunger installation holes 22, respectively.

Next, a work holding operation using the press-fitting device will be described.
In regular holding of the workpiece, the workpiece normal receiving surface 1a is arranged facing the press-fitting head 2 side. At this time, the dog ring 41 is urged forward by the coil spring 40 and is in contact with the front end surface 42 a of the cylindrical portion 42 pressed against the rear end surface of the press-fitting head 2. In addition, factory air or the like is introduced into the air intake port 33 and is discharged from the air discharge port 32 through the air passage 31. At this time, the air pressure of the air passage 31 is measured through the air detection hole 34.

The workpiece 1 is inserted into the introduction cylinder portion 20 through the introduction portion 20 a of the press-fitting head 2. By this insertion, the workpiece 1 is gripped by the ball plunger 25 and the holding acceptance of the workpiece 1 is started (state shown in FIG. 5).
Further, when the insertion of the workpiece 1 is advanced, the inner surface of the workpiece 1 moves rearward along the outer peripheral surface of the introduction cylinder portion 20, and further moves following the workpiece receiving surface 20b. Then, the regular receiving surface 1a of the workpiece 1 presses against the tip of the elongated piece 43 of the dog ring 41, and the dog ring 41 is moved backward against the urging force of the coil spring 40. The air discharge control cylinder portion 44 moves backward with this reverse movement, and finally the air discharge port 32 is closed. In this state, the air discharge port 32 is closed and air is continuously introduced into the air passage 31, so that the air pressure in the air passage 31 increases. This increase in air pressure is detected as a result of air pressure measurement through the air detection hole 34, and it is detected that the workpiece 1 is not held in the normal position. When the workpiece 1 reaches the regular holding position, the regular receiving surface 1a abuts against the workpiece abutting wall portion 21 of the press-fitting head 2 and further movement is restricted, and the movement of the dog ring 41 is also stopped (state of FIG. 6). ). In this state, the air exhaust port 32 and the exhaust port 45 are aligned, and the air in the air passage 31 is exhausted through the air exhaust port 32 and the air pressure in the air passage 31 is reduced. This air pressure is detected as a measurement result of the air pressure through the air detection hole 34, and it is detected that the workpiece 1 is held at the normal position. When the workpiece 1 leaves the normal position, the pressing against the dog ring 41 by the workpiece 1 is retreated or released, so that the dog ring 41 moves forward by the urging force of the coil spring 40, the air discharge port 32 is closed, and the workpiece 1 becomes normal. It is detected that the position is not held. Accordingly, even when the workpiece 1 is held and then dropped, it can be reliably detected. That is, it is easily and accurately detected whether or not the work 1 is properly held by the opening / closing operation of the air discharge port 32 by the forward / backward movement of the dog ring 41.
According to this configuration, it is possible to detect a state where the openings of the air discharge port 32 and the exhaust port 45 are not completely aligned, for example, when the work is inserted at an angle, and it is possible to detect regular holding more accurately. it can. That is, the air discharge port 32 is opened during normal holding, and the air discharge port 32 is closed during non-regular holding.

On the other hand, when the workpiece 1 is inserted into the press-fitting head 2 from the non-regular surface 1b side as shown in FIG. Insertion becomes difficult. That is, the workpiece receiving surface 20b also corresponds to a regulated shape portion that regulates irregular acceptance of workpieces.
In the workpiece 1 whose insertion is restricted as described above, the dog ring 41 is not pressed, so that the air discharge port 32 remains open, and it is detected that the workpiece is not held in the normal position. As a result, the workpiece is not held in an irregular posture, and it is possible to accurately detect whether or not the workpiece is held properly.

The present invention has been described above based on the above embodiment, but the present invention is not limited to the description of the above embodiment, and can of course be modified without departing from the scope of the present invention. It is.

It is sectional drawing and side view which show one Embodiment of this invention. Similarly, it is sectional drawing and the side view which show the detail of a press-fit head. Similarly, it is the front view and sectional drawing which show the detail of a head mounting rod. Similarly, it is a perspective view which shows a dog ring. Similarly, it is sectional drawing which shows the state which hold | maintains and accepts a workpiece | work in a press-fitting apparatus. Similarly, it is sectional drawing which shows the state which hold | maintained the workpiece | work normally to the press-fitting apparatus. Similarly, it is sectional drawing which shows the state which received the workpiece | work into the press-fitting apparatus irregularly.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Work 1a Regular reception surface 1b Non-regular surface 2 Workpiece press-fit head 3 Head mounting rod 20 Introduction cylinder part 20a Introduction part 20b Work reception surface 21 Work contact wall part 23 Sliding groove 31 Ventilation path 32 Air discharge port 33 Air intake port 34 Air Pressure Detection Hole 35 Sliding Cylinder 40 Coil Spring 41 Dog Ring 42 Cylinder 43 Extending Piece 44 Air Discharge Control Cylinder 45 Exhaust Port

Claims (4)

A workpiece holding head for holding the workpiece, the workpiece holding head having a receiving shape portion that enables holding of the workpiece corresponding to normal holding of the workpiece; A detection member that slides with the detection member, and an air discharge port that is opened and closed as the detection member slides and is open when the detection member is not slid. A normal holding detecting means for detecting whether the normal holding of the workpiece is normal or not by an air ventilation operation, and the detection member slides as the workpiece is held and is not held normally. A work holding apparatus , wherein the air discharge port is closed and the air discharge port is opened in a state of sliding in accordance with normal holding of the work. The workpiece holding apparatus according to claim 1 , wherein the workpiece holding head has a restriction-shaped portion that regulates irregular acceptance of the workpiece. The workpiece holding device according to claim 1, wherein the detection member is restricted from sliding in a state where the workpiece is normally held. The detection member has an exhaust port that communicates with the air discharge port in a state where the workpiece is normally held by the sliding, and does not communicate with the air discharge port when the workpiece is not normally held. The work holding device according to claim 1, wherein

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