JPH0345134Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a jig for fixing a piston ring when measuring the roundness of a piston ring attached to a piston of an engine or the like.

(Prior Art) Generally, a piston ring is attached to a piston of an engine or the like in order to seal the inside of the cylinder and remove lubricating oil adhering to the inner wall of the cylinder. This piston ring is cut at one point in the ring to accommodate thermal expansion of the piston, and this cut portion is called an abutment. The piston ring is desirably in close contact with the inner wall of the cylinder, and is therefore required to have a perfect circular shape. Therefore, piston rings are inspected to see if they are perfectly round, and those that are too deformed or out of specification are removed.

Conventionally, a fixture 1 as shown in FIG. 6 has been used to measure the roundness of piston rings. This fixing jig 1 has a lower fixing plate 4 placed in the hollow part 3a of a thin-walled cylindrical model ring 3 placed on a surface plate 2, and a peripheral edge on the upper end surface of the lower fixing plate 4. After the piston ring 5 is set, the upper fixing plate 6 is placed, and the holes 4a..., 6a... provided in the lower fixing plate 4 and the upper fixing plate 6 are tightened with screws 7 to fix the piston ring 5. ,
In this state, the piston ring 5 and the upper and lower fixing plates 4 and 6 are taken out from the hollow part 3a of the model ring 3 and measured using a separately provided measuring means such as an air micro gauge. The reference numeral 8 designates a hexagonal wrench that is fitted into a hexagonal hole (not shown) formed at the top of the screw 7 to tighten the screw 7.

(Problems to be Solved by the Invention) However, the conventional piston ring roundness measuring jig as described above has the following problems.

First, the fixing jig 1 is placed in the hollow part 3a of the model ring 3.
If the gap G between the inner periphery of the hollow part 3a and the outer periphery of the fixing jig 1 is not made constant when setting the piston ring 5, it is impossible to make the piston ring 5 protrude from the outer periphery of the fixing jig 1 by a certain width and to fix it accurately. I couldn't do it. Also,
Even if the positioning of the piston ring 5 and the fixing jig 1 can be performed accurately, the piston ring 5 will be bent outward from the cut part of the abutment part 5a by tightening the screws 7, causing deformation and causing accurate positioning. Since the shape is not fixed, there is a problem in that accurate measurements cannot be made. Incidentally, the measurement results based on the above conventional example are as shown in FIG. 7, and it can be seen that the abutment portion 5a is deformed and fixed.

In addition, in connection with the above-mentioned problem that the piston ring 5 cannot be fixed accurately, the lower fixing plate 4 and the piston ring 5 are disposed inside the hollow part 3a of the model ring 3.
In the work of setting, the operator often relies on his or her intuition to position the inner periphery of the hollow portion 3a and the outer periphery of the lower fixing plate 4 as a constant gap G.
Accurate positioning requires careful attention and time, and has the problem of poor workability.

Furthermore, after the piston rings 5 have been set on the fixing jig 1, when taking them out from the model ring 3, not only is this removal work complicated, but also the inner periphery of the model ring 3 and the piston ring are removed during the removal work. There was a problem in that a part of the outer periphery of 5 came into contact with each other, causing an error in the set state and making the measurement of roundness inaccurate.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a fixing jig that can accurately fix a piston ring without causing bending or distortion, and can quickly perform the piston ring fixing work. It is an object.

(Means for Solving the Problems) In order to achieve the above problems, the piston ring roundness measuring jig according to the present invention includes a base, a base provided on the base, and a jig for measuring roundness of piston rings according to the present invention. a shaft installed at the center of a hollow portion formed in a base and removably installed on the base; a tapered guide surface placed on the base and having an inner circumferential surface that expands at the top; a fixed plate consisting of a pair of discs having a hole through which the shaft passes in the center and sandwiching the piston ring from above and below by a peripheral edge; and a fixing plate formed on the lower end side of the shaft. a fixing means for fixing the fixing plate and the piston ring with a locking part; a bearing provided between the fixing means and the fixing plate; and a releasing means for removing the lower end of the shaft from the base. It is characterized by being constructed by.

(Function) With the above configuration, the piston ring guided by the piston ring positioning member can
It is held in such a way that it evenly protrudes from the peripheral edges of the pair of fixing plates, and is fixed by the fixing means to the locking part of the shaft with an even tightening force.

Furthermore, the lower end of the shaft erected on the base can be removed from the base by a release means.

With the above-mentioned action, the piston ring can be fixed accurately without bending or distortion, which eliminates the negative influence of the fixing jig on the roundness of the piston ring, and also allows the fixing means to Therefore, the fixing plate and piston ring that are integrally fixed to the shaft can be quickly removed by the release means and used for measuring the roundness, so the jig for measuring the roundness of piston rings is highly accurate and has excellent workability. can be provided.

(Example) The piston ring roundness measuring jig having the purpose, structure, and function described above will be described in more detail using an example.

1 to 5 are for explaining one embodiment of the present invention.

In FIGS. 1 and 2, a fixing jig 10 has a cylindrical base 12 fixed onto a base 11 with pins 13. As shown in FIGS. A shaft 14 is erected at the center of the hollow portion 12a of the base 12. A shaft fixing member 15 for erecting the shaft 14 is provided within the hollow portion 12a and on the base 11.
are fixed with screws 16. Further, a flange portion 14a is formed on the lower end side of the shaft 14, and a hole 14b and a hole 1 are formed at corresponding locations between the flange portion 14a and the shaft fixing member 15.
A dowel pin 17 is engaged with each of the holes 14b and 15a to prevent the shaft 14 from rotating within the center hole 15b of the fixing member 15. A notch 1 is provided inside the upper end of the base 12.
2b is formed, and this notch step portion 12b has a tapered guide surface 18a that expands upward on the inner peripheral side.
The protruding portion on which the model inner circumferential surface 18b of the piston ring positioning member 18 is formed is fitted.

A bearing 1 is provided on the upper part of the flange portion 14a.
9a is fitted into the upper part of this bearing 19a, and a center hole 20c of a disc-shaped lower fixing plate 20 having a convex part 20a on the lower surface and a recessed part 20b on the upper surface is fitted into the upper part of this bearing 19a.
On the upper part of this lower fixing plate 20, a lower fixing plate 20 is provided.
The center hole 21c of the upper fixing plate 21, which has a substantially symmetrical shape, is fitted into the center hole 21c. Therefore, the upper fixing plate 21 has a convex portion 21a on the upper surface and a recessed portion 21b on the lower surface. The pair of upper and lower fixing plates 20 and 21 each have a peripheral edge portion 20
The piston ring 5 is held between d and 21d. Convex portion 21a on the upper surface of the upper fixing plate 21
A bearing 19b is fitted onto the shaft 14 at the top, and a nut 22 is screwed onto the top of the bearing 19b.

At the top of the base 12 and the positioning member 18,
A support member 23 having a flange 23a at the lower end periphery is placed. This support member 23 has a cap-like cylindrical shape, and the center of the top plate 23b is a protrusion 23c that protrudes upward.
The shaft 14 is inserted into the hole 23d drilled in the hole 3c.
The upper end 14c of is penetrated. A nut 24 is screwed into the upper end 14c of the shaft. The top plate 23b of the support member 23 has a protrusion 2.
Holes 23e are bored to surround 3c.

The operation of fixing a piston ring using the piston ring fixing jig 10 having the above configuration will be described.

First, as shown in FIG. 3, the shaft 14 is set upright in the center hole 15a of the shaft fixing member 15 in the center hole 11a of the base plate 11, and its rotation is restricted by the dowel pin 17. Next, from the model inner circumferential surface 18b of the piston ring positioning member 18 on the base 12, the bearing 19a and the lower fixing plate 20 are sequentially removed from the shaft 1.
4 and set it. Subsequently, when the piston ring 5 is dropped, the piston ring 5 is guided along the tapered guide surface 18a of the positioning member 18 and fits into the model inner peripheral surface 18b. In this way, the piston ring 5 is positioned with its outer edge uniformly protruding from the peripheral edge 20d of the lower fixing plate 20.

After setting the piston ring 5 as described above, the upper fixing plate 21, the bearing 19b
When the piston ring 5, upper and lower fixing plates 20 and 21, and bearings 19a and 19b are tightened between the shaft flange portion 14a and the shaft flange portion 14a using the nut 22, the piston ring 5 is fitted onto the shaft 14 as shown in FIG. Fixing is complete. At this time,
Bearings 19a, 19b and fixed plates 20, 21
Since the tightening force of the nut 22 is alleviated in the rotational direction by the convex portions 20a, 21a and the concave portions 20b, 21b, no unnecessarily deforming force is applied to the piston ring 5.

Next, a process of removing the above-mentioned members fixed by the flange portion 14a of the shaft 14 and the nut 22 from the center hole 15b of the shaft fixing member 15 will be described. As shown in FIG.
This support member 23 is fitted onto the shaft 14.
When the nut 22 is screwed onto the upper end 14c of the shaft that protrudes upward from the protrusion 23c, the nut 22
The shaft 14 is raised by the support of the base 11, the base 12, the positioning member 18, and the support member 23, and the lower end can be gradually pulled out from the center hole 15a. At this time, the flange portion 14a of the shaft 14
Since the dowel pin 17 is inserted through the flange portion 1 to prevent the shaft from rotating, the shaft 14 rises without rotating, and the upper end of the dowel pin 17 touches the flange portion 1.
By moving away from 4a, the positioning is released and becomes free. The shaft 14, to which the piston ring 5 is fixed with high precision in this manner, is attached to the base 1.
Since it is canceled from 1, it becomes possible to measure using an air micro gauge for measurement.

Piston ring 5 measured as above
The measurement results are shown in the characteristic diagram of FIG. This measurement result is different from that measured by fixing it with the conventional fixing jig 1 shown in Fig. 7, even though the roundness of the same piston ring 5 is being measured. There is a significant difference in accuracy. That is,
Based on the difference in these measured values, the piston ring 5 is
Although it was manufactured as a substantially perfect circle separated by a, it was found that it was distorted during the inspection stage, especially when it was set in the fixing jig, and correct measurement values could not be obtained.

Effects specific to the embodiments described above will be explained in detail.

First, recesses 20b and 21b are formed on the abutting surfaces of the upper and lower fixing plates 20 and 21 that sandwich the piston ring 5, and convex portions 20 are formed on the surfaces other than the respective abutting surfaces.
Since the fixing plates 20 and 21 have elasticity in the direction of the opposite surface when the piston ring 5 is clamped, this elasticity allows the nut 2
Since the tightening force of 2 is relaxed, the piston ring 5
The piston ring can be accurately fixed without the risk of being ejected from between the fixing plates 20 and 21 toward the outer circumference or deforming the piston ring 5.

In addition, the shaft fixing member 15 and the shaft 14
Knock pin 17 inserted through the flange portion 14a of
Since the shaft 14 is fixed so that it will not rotate even when the nuts 22 and 24 are screwed in, it is possible to prevent the rotation of the shaft 14 and the fixed plates 20 and 21, and there is no space between the fixed plates 20 and 21. Model inner circumferential surface 1 of the piston ring positioning member 18 that is clamped
The piston ring 5 in contact with the shaft 14 rotates following the rotation of the shaft 14, and the model inner peripheral surface 1
It is possible to prevent misalignment caused by collision between 8b and the outer circumferential surface of the piston ring 5.

Furthermore, the piston ring 5, which is positioned and fixed by providing the support member 23 and screwed into the nut 24, is lifted vertically from the exemplary inner circumferential surface 18b of the piston ring positioning member 18 together with the upper and lower fixing plates 20, 21. Since the outer periphery of the piston ring 5 can be taken out without colliding with other members, the shape of the piston ring can be accurately fixed and used for measurement with a simple configuration.

In addition, holes 23e in the top plate 23b of the support member 23...
After the piston ring 5 is removed from the model inner circumferential surface 18b of the positioning member 18, when the fixing plates 20, 21 and the piston ring 5 fixed by the shaft 14 and the nut 22 are removed, the above-mentioned It has the unique effect that it can be lifted by inserting a finger into the hole 23e, making the removal operation easier.

It should be noted that what has been described above is one embodiment of the present invention, and any changes may be made without departing from the purpose, structure, and effects of the present invention.

For example, in the above embodiment, the shaft fixing member 15 is provided on the base 11, but the shaft may be erected directly on the base.

Further, a flange portion 14 is provided on the lower end side of the shaft 14.
Although the embodiment has been described as being provided with a nut, the present invention is not limited to this. For example, a nut whose rotation is restricted by a dowel pin or the like may be provided on the lower side to fix the fixing plate, piston ring, and bearing.

Note that the tapered guide surface 18a and the model inner circumferential surface 18
By preparing a variety of piston ring positioning members 18 having the shape b according to the size of the piston ring, it is possible to select and use a member suitable for each size. In addition, the upper and lower fixing plates 20, 21
Similarly, various sizes of piston rings are prepared to correspond to various types of piston rings.

(Effects of the invention) As described above in detail, the piston ring roundness measuring jig according to the invention provides the following effects.

First, a fixing plate for the piston ring is installed on a shaft that stands upright in the center of the hollow part of the base provided on the base, and the piston ring is fixed by a positioning member having a tapered guide surface placed on the base. Since the fixed plate is fixed uniformly by the fixing means through the bearing, the outer circumferential surface of the piston ring is uniformly protruded from the peripheral edge of the fixed plate due to the shape of the molded side of the piston ring. Since it can be fixed, the roundness of piston rings can be measured accurately.

In addition, since the shaft is installed upright in the center of the base, the centers of the positioning member and the fixed plate are aligned with each other, and the piston ring can be accurately placed on the fixed plate simply by feeding it from the tapered guide surface. So,
It is also possible to improve the workability of positioning the piston rings.

Furthermore, since a release means for removing the lower end of the shaft from the base is provided on the upper side of the shaft, when removing the piston ring held between the fixed plates from the model inner circumferential surface of the piston ring positioning member, the inner circumferential surface and the piston There is no possibility that the outer circumference of the piston ring is locally displaced within the fixed plate due to collision with the outer circumferential surface of the ring, and highly accurate measurement and speedy work can be achieved in this respect as well.

[Brief explanation of the drawing]

Figures 1 to 5 illustrate an embodiment of the piston ring roundness measuring jig according to the present invention, and Figure 1 is a front partially cutaway sectional view showing the entire fixing jig. , FIG. 2 is a plan view, FIGS. 3 and 4 are sectional views showing the process of fixing the piston ring to the fixing jig, and FIG. 5 is a diagram of the piston ring fixed by the measuring jig of this example. It is a characteristic diagram showing measured values. Further, FIG. 6 is a sectional view showing an example of a conventional measuring jig, and FIG. 7 is a characteristic diagram showing measured values of a piston ring fixed by the same jig. 5... Piston ring, 10... Roundness measuring jig (fixing jig), 11... Base, 12... Base,
14... Shaft, 14a... Locking part (flange part), 18... Positioning member, 18a... Tapered guide surface, 18b... Model inner peripheral surface, 19a, 19
b...Bearing, 20...Lower fixing plate, 21...
...Upper fixing plate, 22...Fixing means (nut), 2
3, 24...Release means (support member, nut).

Claims (1)

[Scope of utility model registration request] a base, a base having a hollow part provided on the base; a shaft installed removably at the center of the hollow part on the base; a shaft placed on the base; A piston ring positioning member having an upwardly expanding tapered guide surface on the upper part of the model inner circumferential surface, and a pair of circles having a hole in the center through which the shaft passes, and sandwiching the piston ring from above and below at the peripheral edge. A fixing means for fixing the fixing plate and the piston ring between the plate-shaped fixing plate and a locking part formed on the lower end side of the shaft, and a fixing means provided between the fixing means and the fixing plate. bearing and
A jig for measuring the roundness of a piston ring, comprising a releasing means for removing the lower end of the shaft from the base.