JPH0611758Y2 - Work positioning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a work positioning device. INDUSTRIAL APPLICABILITY The present invention can be used for a positioning device of a grinding device for grinding a work surface of a valve (workpiece) of an EFI (electronically controlled fuel injection device) of an automobile.

[Prior Art] Workpieces, for example, vehicles have conventionally been provided with EFI valves.

As shown in FIG. 4, this valve W has a tubular valve body W1 having a central hole W10 and a seating surface W11 on the inner surface forming the central hole W10, and a shaft portion W20 (inserted into the central hole W10. ) And a head W21 (not inserted into the central hole W10), and a needle W having an engaging surface W22 on the shaft W20 and an engaging surface W22 engaging the seating surface W11.
It consists of 2.

In this valve W, the ground surface W12 as the surface to be processed of the valve body W1 and the flange surface W2 of the shaft W20 of the needle W2.
Dimension L between 3 and 3 (shown in FIG. 4) requires extremely high accuracy.

By the way, conventionally, in a grinding device for grinding a grinding surface W12 as a surface to be processed of a valve body W1 of EFI, as shown in FIG. With the end surface W24 as a reference surface,
At the same time, the end surface W13 of the valve body W1 is moved to the first biasing member 10
The seating surface W11 of the valve body W1 is engaged with the engaging surface W22 of the needle W2 by urging it to 0, thereby positioning the grinding surface W12 during grinding. Then, the valve body W1 is fixed by the chuck 10 in the thus positioned state, and the grinding surface W1 is fixed in this state.
It was grinding by applying a whetstone to 2.

At this time, in order to secure the accuracy of the dimension L described above, the fourth
As shown in the figure, the measuring elements 103 and 104 are applied to the grinding surface W12 and the collar surface W23, respectively.
Is being measured.

However, the grinding surface W1 of the valve body W1 of the valve W
The position of 2 in the axial direction varies due to the preceding process, and the axial dimension M of the head W21 of the needle W2 is M.
Due to the dimensional tolerances (see FIG. 4), the grinding surface W1
When determining the position of 2, the position of the grinding surface W12 may be slightly shifted in the axial direction by the above-mentioned dimensional tolerance.

In this way, in the case where the position of the grinding surface W12 is displaced in the axial direction, it is necessary to determine the grinding start position of the grindstone in anticipation thereof, so the grinding feed stroke increases,
Therefore, the cycle time increases and the production efficiency decreases.

[Problems to be Solved by the Invention] The present invention has been made in order to solve the above-mentioned problems, and an object thereof is to accurately set the positioning of a work surface of a workpiece. Accordingly, it is an object of the present invention to provide a work positioning device capable of improving the production efficiency.

[Means for Solving the Problems] A work positioning device according to the present invention includes a rotatable chuck for fixing a work and a work fixed on the chuck in the axial direction of the work by a first biasing force. A work holding device having a first urging member that urges toward one side, and is provided on the opposite side of the first urging member via the work in the axial direction and abuts on the work surface of the work. A reference part having a machining reference surface and capable of advancing toward the other in the axial direction and retracting toward the other in the axial direction, and a workpiece that is movably held in the axial direction through the reference part. Positioning of a gripping part that is sandwiched by a biasing member, a second biasing member that biases the gripping part in a direction facing the first biasing member with a second biasing force that is weaker than the first biasing force, and a workpiece. Sometimes the reference part is moved to the fixed position in the other axial direction and the workpiece is machined. A transfer device having a reciprocating drive device for retracting in the axial direction of the other reference portion and is characterized in that it consists of.

As described above, the workpiece is a cylindrical valve body having a central hole and a seating surface on the inner surface forming the central hole, a shaft portion fitted in the central hole, and a head portion not fitted in the central hole. And a needle having an engaging surface on the outer peripheral surface of the shaft portion, the first biasing member and the second biasing member bias the workpiece from opposite directions. The seating surface of the valve body and the engaging surface of the needle are seated by doing so, and in the state where the valve body is seated in this way, the reference part covers the head of the valve body from the outside and the processing reference of the reference part. It is desirable that the surface be in contact with the surface to be processed of the valve body.

[Operation] In the positioning device according to the present invention, when positioning a workpiece, the reference portion is advanced in one axial direction while the workpiece reference surface of the reference portion is in contact with the workpiece surface. Here, the forward position of the reference portion is a fixed position in the axial direction,
Moreover, since the workpiece is urged by the first urging member in the direction opposite to the forward direction of the reference portion, the work surface of the workpiece is stopped at a fixed position.

[Embodiment] An embodiment of the present invention is shown in FIGS.

The workpiece positioning apparatus of this embodiment is the E of the automobile described above.
This is a case where the invention is applied to a grinding device that grinds a grinding surface as a work surface of a valve body that is a component of a FI valve.

(Structure) The positioning device according to the present embodiment includes a work holding device 1 rotatably supported by a headstock installed on a bed (not shown), a work holding device 1 and an axially separated bed. The transfer device 2 is installed above.

The workpiece holding device 1 includes a chuck 10 and a first biasing member 1
With 1.

The chuck 10 is an air chuck called a microcentric chuck and is operated by air. The first urging member 11 is composed of a coil-shaped first spring 110 arranged in the central hole 10a and a pressing metal 111 held at the tip of the first spring 110. The tip surface of the pressing metal 111 is smooth. This is because the valve W is pressed.

A gauge device 12 is provided on the bed. As shown in FIG. 3, the gauge device 12 has a valve body W1.
The first measuring element 120 applied to the ground surface W12 as the surface to be processed and the second measuring element 121 applied to the collar surface W23 of the needle W2. Here, as shown in FIG. 5, a displacement detector 123 such as an operating transformer for detecting the displacement of each of the tracing stylus 120 and 121,
Measuring elements 120 and 121 are connected to 124.
The output signals of the displacement detectors 123 and 124 are output to the amplifier 12
After being amplified by 5, 126, it is given to the arithmetic circuit 127 to calculate the present dimension between the collar surface W23 and the grinding surface W12, and the signal from the arithmetic circuit 127 is used as a signal from the comparison circuit 1.
28, and the comparison circuit 128 compares the signal level with respect to the set value.
Is output. The output signal of the amplifier 126 is the comparison circuit 1
29, the comparison circuit 129 compares the set value with the set value, and when the set value matches the set value, the sizing signal AS1 is output. Then, the sizing signals AS1 and AS2
The drive of the grindstone 30 to be described later is controlled by.

The transfer device 2 includes a base 20, a transfer arm 21, a grip 22, a second biasing member 23, and a reference 24.

The base 20 includes a tailstock 200, a tailstock ram 201 held by the tailstock 200 so as to be able to move forward and backward, and a tailstock ram 2.
01 and a rotating shaft 203 rotatably supported by a bearing 202 and having a tapered surface 204a;
and a cylindrical portion 205 that is taper-fitted to a. The rotary shaft 203 rotates in the same direction at the same speed as the work holding device 1 via a synchronous shaft (not shown) inserted in the synchronous shaft cover 300.

The transfer arm 21 transfers a valve W as a workpiece to a position corresponding to the workpiece holding device 1, and is rotated about a support shaft 215 by a rotating cylinder 210. As shown in FIG. 1, it is transferred to a position corresponding to the work holding device 1.

The grip portion 22 is held by the tubular portion 205 so as to be movable in the axial direction, and has a rod 220 that presses the head W21 of the needle W2 of the valve W and grips the valve W with the pressing gold 111. . The rod 220 has an elongated shape and has a tubular portion 205.
Is inserted in the central hole of the.

The second biasing member 23 includes a coil-shaped second spring 230 and a bush 231. The second spring 230 is
The biasing force is weaker than the biasing force of the first spring 110, and the biasing force biases the rod 220 in the direction of arrow A, that is, in the direction opposite to the biasing force of the first spring 110.

The reference portion 24 is arranged on the tailstock ram 201 side and is formed in the cylinder chamber 201a formed at the tip of the rotary shaft 203.
Inside, there is a reference metal 240 formed of a cylindrical cylinder piston held so as to be able to advance in the direction of arrow A. This standard gold 2
A third spring 241 that constitutes an advancing / retreating drive device that urges 40 in a direction opposite to the urging direction (arrow B direction) of the first spring 110 of the first urging member 11 is provided.

The cylindrical reference gold 240 has an inner diameter larger than the diameter of the head W21 of the needle W2 of the valve W, and fits the head W21 from the outside. The cylinder chamber 201a is connected to an air source (not shown), and the reference portion 24 is connected to the first biasing member 11
Drive in the axial direction urged by and move backward. The biasing force of the third spring 241 is set to be larger than the biasing forces of the second spring 230 and the first spring 110.

Here, the cylindrical reference gold 240 has the processing reference surface 24 at the tip.
It has a vertical surface 240b in the center. Therefore, when the reference metal 240 advances in the direction of arrow A in the cylinder chamber 201a by the urging force of the third spring 241, the vertical surface 240b abuts and the processing reference surface 240a has a fixed position F.
It is set to stop at (see FIG. 3).

(Operation) When using the workpiece positioning apparatus according to the present embodiment, the valve W is housed in the holding cylinder 210 of the transfer arm 21 and the valve W in the holding cylinder 210 is held by rotating the transfer arm 21. Set it so that it is almost aligned with the axis of the device. In this state, the air in the cylinder chamber 201a is opened to the atmosphere, the reference gold 240 of the reference portion 24 is advanced in the direction of arrow A by the urging force of the third spring 241, and the tailstock ram 201 is advanced by a certain amount. Then, as shown in FIG. 3, the reference gold 240 has the head W21.
From the outside, the processing reference surface 240a of the reference gold 240
Thus, the grinding surface W12 as the work surface of the valve body W1 of the valve W is pressed, and the head W21 of the needle W2 is pressed.
However, since it is pressed by the rod 220, the valve W is
As shown in the figure, the transfer arm 21 to the workpiece holding device 1
Is inserted into the central hole 10a.

At this time, as described above, the reference gold 240 of the reference portion 24
Is set to stop at a fixed position F, and as can be understood from FIG. 3, the first spring 110 of the first biasing member 11 biases the valve W as a workpiece in the direction of arrow B. In order to urge, the grinding surface W12 of the valve body W1 is pressed against the processing reference surface 240a by the first spring 110,
The grinding surface W12 is reliably set at the fixed position F.

In this state, as shown in FIG. 1, the first biasing member 11
Since the second urging member 23 and the second urging member 23 urge the valve W as a workpiece from mutually opposite directions, as shown in FIG.
The seating surface W11 of the valve body W1 and the engaging surface W22 of the needle W2 are seated in close contact with each other. When the seating surface W11 of the valve body W1 and the engagement surface W22 of the needle W2 are seated in this manner, the reference portion 24 covers the head W21 of the valve body W1 from the outside.

In the present embodiment, as shown in FIG. 3, even when there is a dimensional tolerance in the axial dimension M of the head W21 of the needle W2 of the valve W, the axial dimension M of the head W21 becomes smaller. As described above, the grinding surface W12 of the valve body W1 is reliably stopped at the fixed position F regardless of the dimensional tolerance. In this state of positioning, as shown in FIG. 1, the outer peripheral portion of the valve body W1 of the valve W is fixed by the chuck 10. If fixed in this way, the balf W cannot move in its axial direction. This is because the first urging member 11 and the second urging member 23 urge the valve W as a workpiece from opposite directions.

In this fixed state, the air cylinder constituting the advancing / retreating drive device is operated to move the reference portion 24 backward along the arrow B direction. Then, the grindstone 30 of the grindstone base is fast-forwarded to be brought close to the grinding surface W12 of the valve W and set at a predetermined grinding start position. At this grinding start position, the grinding surface of the grindstone 30 is in contact with the grinding surface W12 of the valve W or is very close thereto.

Then, in this state, the work holding device 1 is rotated to rotationally drive the valve W. At this time, the rotary shaft 203 in the tailstock ram 201 also rotates in the same direction at the same speed via the synchronous shaft. At this time, the needle W2 of the valve W is pressed and grasped by the rod 220 biased in the direction of the arrow A by the third spring 241, so that the seating surface W11 of the valve body W1 and the engaging surface W22 of the needle W2. Remains closely seated with.

While the valve W is thus rotated, the grinding surface W12 of the valve W is ground by driving the grindstone 30. At this time, the second tracing stylus 121 is brought into contact with the collar surface W23,
The stylus 120 is brought into contact with the grinding surface W12 and grinding is performed while measuring the dimension between the flange surface W23 and the grinding surface W12.

(Effect) With the positioning device according to the present embodiment, it is possible to directly position the ground surface W12, which is the surface to be processed of the valve W, as the reference surface. Therefore, the head W2 of the valve W
Even if there is a dimensional tolerance in the axial dimension M of 1,
The grinding surface W12 of the valve W can be positioned regardless of the dimensional tolerance. Therefore, unlike the prior art, in the present embodiment, the feed stroke of the grinding wheel head 3 is shortened accordingly, and therefore the cycle time can be shortened, which contributes to the improvement of the production efficiency.

[Advantage of the Invention] According to the positioning device of the present invention, it is possible to directly position the surface to be processed such as the valve W as the reference surface. Therefore, even if there is dimensional tolerance in the axial dimension of the workpiece such as the valve W, the workpiece surface of the workpiece such as the valve W can be positioned regardless of the dimensional tolerance. Therefore, unlike the conventional case, when applied to a grinding machine having a wheel head, the feed stroke of the wheel head is reduced accordingly, and therefore the cycle time can be shortened, which contributes to the improvement of production efficiency. be able to.

[Brief description of drawings]

FIG. 1 is a cross-sectional side view of a main portion according to the present embodiment, showing a state where a valve grinding surface is ground, and FIG. 2 is a longitudinal section showing a valve grinding surface being positioned. It is a side view. FIG. 3 is an enlarged vertical sectional view showing a state where the grinding surface of the valve is positioned. FIG. 4 is an enlarged vertical sectional view showing a state in which the positioning is performed using the conventional positioning device. FIG. 5 is a circuit diagram in which the first probe and the second probe are connected. In the figure, 1 is a work holding device, 10 is a chuck, 11 is a first biasing member, 110 is a first spring, 111 is a bush, 2 is a transfer device, 21 is a transfer arm, 22 is a gripping part, 2
20 is a rod, 23 is a second biasing member, 230 is a second spring, 231 is a bush, 24 is a reference portion, 240a is a processing reference surface, 241 is a third spring, 242 is a tubular portion,
W indicates a valve body (workpiece), and W12 indicates a grinding surface (working surface).

Claims (2)

[Scope of utility model registration request] 1. A rotatable chuck for fixing a workpiece,
A workpiece holding device having a first biasing member for biasing a workpiece fixed to the chuck toward one side in the axial direction of the workpiece with a first biasing force, and a workpiece in the axial direction via the workpiece. Is provided on the side opposite to the first urging member and has a machining reference surface that comes into contact with the surface to be machined of the workpiece, and is provided so as to be able to advance toward the other side in the axial direction and retract toward the one side in the axial direction. A reference portion, a gripping portion that pierces the reference portion and is movably held in the axial direction to sandwich the workpiece with the first biasing member, and a second weaker than the first biasing force. A second urging member for urging the gripping portion in a direction facing the first urging member by an urging force; and advancing the reference portion to a fixed position toward the other in the axial direction when positioning the workpiece. And an advancing / retreating drive device for retracting the reference portion toward the other side in the axial direction when machining the workpiece. A work positioning device comprising: a feeding device. 2. The reference portion has a cylindrical shape, and the workpiece is fitted into the central hole of the valve body and a cylindrical valve body having a seating surface on the inner surface forming the central hole. The first urging member and the second urging member are formed of a needle having a shaft portion and a head not fitted in the central hole and having an engaging surface on an outer peripheral surface of the shaft portion. The seating surface of the valve body and the engaging surface of the needle are seated by bringing the seating surface of the valve body into close contact with each other by urging the workpieces from opposite directions, and the seating surface of the valve body and the engaging surface of the needle. Claims for utility model registration wherein the reference portion covers the head portion of the valve body from the outside in a state where and are seated, and the processing reference surface of the reference portion abuts the surface to be processed of the valve body. The workpiece positioning device according to item 1.