JPH07908Y2 - Piston ring tension measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to the structure of a device for measuring the tension of a combined piston ring used for a piston in an engine.

[Conventional technology]

The pressure exerted on the inner peripheral surface of the bore when the piston ring, which is formed by cutting one end of the ring body and having a fitting gap of appropriate size, is inserted in the ring groove of the piston in the engine and is fitted in the cylinder bore of the engine. If the (tension force) is too large, the oil film on the inner peripheral surface of the bore will run out, and if it is too small, pressure gas leakage in the combustion chamber of the engine and oil rising into the combustion chamber will occur, and in either case there is a problem. Occurs.

Therefore, in order to adopt only the product having a proper tension force of the completed piston ring as a good product, the tension measurement, which is one of the product inspections of the piston ring, is executed.

This tension measurement is a force in the circumferential tangential direction at the abutment portion, which is proportional to the radial outward pressing force (tension force) with which the outer peripheral surface of the piston ring contacts the inner surface of the bore (hereinafter this force is referred to as tension).
As a prior art of the measuring device, the applicant previously described in Japanese Utility Model Application Laid-Open No. 59-25443, pivotally attaches one end of a pair of semicircular ring-shaped frame bodies in plan view. On the inner diameter side of the pair of frame bodies, a large number of contact bodies such as balls and columnar pins that come into contact with the outer peripheral surface of the piston ring for measurement and have a small sliding contact resistance are circumferentially arranged at appropriate intervals. The piston ring is sandwiched between the pair of frame bodies, and the one frame body is tightened so that the radius is contracted with respect to the other frame body, and the gap distance of the abutment portion of the measured piston ring is a predetermined value. We have proposed a device to measure the tightening force when it becomes.

[Problems to be solved by the device]

By the way, recently, as a piston ring such as a so-called oil ring which is fitted into an annular ring groove provided on the outer periphery of a piston in an engine, a spacer expander formed by bending a flat metal plate into a substantially trapezoidal cross section, and a spacer expander thereover Various types have been developed in which a pair of upper and lower side rails arranged on the lower surface are arranged in a combined state in the ring groove and the outer peripheral end surfaces of the pair of side rails are brought into sliding contact with the inner surface of the bore.

When measuring the tension of this type of combination piston ring,
In order to use the above-mentioned measuring device of the prior art, first, a disc-shaped assembling jig in which a ring groove having the same size as the annular ring groove of the piston is formed is prepared, and the inside of the ring groove of the assembling jig is prepared. The built-in combination type piston ring to be measured is installed in advance, and the outer peripheral surface of the combination type piston ring is fitted to the inner peripheral side of the pair of frame bodies together with this built-in jig, and the pair of frame bodies is used to measure the object to be measured. It is conceivable to tighten the outer peripheral surface of a certain piston ring for measurement, but simply using such a built-in jig would cause the following inconveniences.

That is, this type of combination piston ring supports a pair of upper and lower side rails having a thickness smaller than the vertical dimension of the ring groove of the piston on the upper and lower surfaces of a spacer expander having a complicated cross-sectional shape, and When the elastic force of the spacer expander acts so that the upper and lower projections on the inner peripheral side of the panda press the inner peripheral ends of the side rails radially outward, the outer peripheral surfaces of the both side rails are the inner surface of the bore. Since the upper and lower side rails and the spacer expander are simply assembled in the ring groove, the side rails may not be arranged substantially parallel to each other or the inner peripheral side of the spacer expander may be pressed. Both the upper and lower projections of the side do not mesh properly so as to contact the inner peripheral edge of each side rail, etc. Hardly, therefore, measured tension value of the result likely error occurs, there is a problem of lack of reliability.

The present invention has been made in view of such circumstances, and an object thereof is to provide a measuring device for a piston ring capable of obtaining an accurate measured value.

[Means for Solving the Problems]

In order to achieve this object, the present invention provides a disc-shaped assembling jig in which a combination type piston ring, which is an object to be measured, is fitted in a ring groove on the outer circumference, and the assembling jig is tightened from the outer circumference to detect the tightening force. A pair of frame bodies for supporting and a support table for mounting these, and in the pair of frame bodies, a pressing body having a small radius of curvature that comes into contact with the outer peripheral surface of the combination piston ring is combined. A large number of the plurality of frame bodies are provided at appropriate intervals along the circumferential direction of the piston ring, and one frame body of the pair of frame bodies is fixed to a support base, and the other frame body is provided at the base end of the fixed frame body The base end portion of the above is horizontally rotatably connected, and a friction reducing means is interposed between the lower surface of the assembling jig and the upper surface of the supporting base, and the vibrating means applies vibration to the supporting base. It is composed.

[Function and effect of device]

With this configuration, the upper and lower side rails and the spacer expander of the combined piston ring that is the DUT can be installed in the ring groove of the built-in jig in advance. Since it can be attached / detached to / from the measuring device, setup such as measurement preparation work can be efficiently performed.

The outer peripheral surfaces of the upper and lower side rails of the combination type piston ring are, in a state of being assembled in an assembling jig, a large number of pressing bodies with small radii of curvature in a pair of left and right frame bodies that tighten the assembling jig from the outer diameter side. Since it is tightened to a predetermined diameter in a point contact or line contact state, the frictional resistance due to contact can be extremely reduced.

Further, since the support base is vibrated by the vibrating means and the friction reducing means is interposed between the support base and the assembling jig, the spacer in the state of being assembled in the ring groove of the assembling jig is used. The difficulty of fitting at the contact portion between the expander and both upper and lower side rails can be eliminated very easily by shaking the built-in jig through the friction reducing means by the vibration applied to the support base.

Furthermore, by interposing a friction reducing means such as a ball between the support base and the built-in jig, the built-in jig can be moved relative to the vibrating left and right frame bodies. In this state, the outer peripheral surfaces of the upper and lower side rails, which have a small thickness, have been made difficult to fit into the contact surface with the surface of the pressing body, and the combination type piston ring has been corrected to a normal posture, resulting in unnatural contact between parts. An increase in frictional force can be eliminated.

Therefore, according to the present invention, there is a remarkable effect that the tension of the combination type piston ring can be measured efficiently and accurately.

[Embodiment] Next, an embodiment will be described. In FIGS. 1 and 2, reference numeral 1 is a downward U-shaped section which is placed on a base 2 of a tension measuring device via a plurality of springs 3. Reference numerals 4 and 4'indicate support bases, and a pair of left and right plan view substantially semicircular annular frames that sandwich the outer peripheral surface of the combination type piston ring 6 which is the object to be measured incorporated in the later-described assembling jig 5 from the outside. It is the body.

An example of the combination type piston ring 6 is, as shown in FIG. 3 and FIG. 5, formed in a U-shaped cross section in a metal plate, and has cut grooves 7c and 7d in the outer peripheral portion and the inner peripheral portion, respectively. The spacer expander 7 includes a plurality of spacers alternately provided, an upper side rail 8 made of a flat metal plate, and a lower side rail 9 also made of a flat metal plate. Receiving protrusions 10 and 11 for the both side rails 8 and 9 are integrally formed on the outer peripheral portions of the upper and lower surfaces 7a and 7b, respectively, and the inner peripheral portions of the upper and lower surfaces 7a and 7b of the spacer expander 7 are formed. The press protrusions 12 and 13 having inclined surfaces 12a and 13a with respect to the inner peripheral surfaces of the both side rails 8 and 9 are integrally formed with each other.

The height from the tips of the receiving projections 10 and 11 to the tips of the upper and lower pressing projections 12 and 13, and from the upper and lower surfaces 7a and 7b of the spacer expander 7 to the tips of the upper and lower pressing projections 12 and 13, respectively. Set the height dimension to a value that is appropriately smaller than the thickness of the upper and lower side rails 8 and 9 so that when the piston (not shown) reciprocates, the side rails 8 and 9 are set in the ring groove on the outer circumference of the piston. Even if it is tilted, the tips of both the upper and lower pressing projections 12 and 13 do not come into contact with the ceiling surface and the bottom surface of the ring groove.

In addition, a jig 5 for assembling the combination type piston ring 6
Has a ring groove 14 having the same diameter (D1) as the piston actually used in the internal combustion engine and having the same cross-sectional shape as in the piston, as shown in FIG.
The combination type piston ring 6, which is the object to be measured, is incorporated in the ring groove 14 in advance.

The pair of frame bodies 4, 4 ′ have inner diameter circumferential surfaces facing each other,
In addition, the central axes of the arcs of the frames 4 and 4'are arranged at right angles to the upper surface of the support 1, and one frame 4 is fixed to the upper surface of the support 1 with bolts 16 or the like. On the other hand, the other frame body 4'is pivotally attached at its base end portion to the base end portion of the one frame body 4 via a support shaft 17.

When the two frame bodies 4 and 4'approach each other on the inner peripheral surfaces of the pair of frame bodies 4 and 4 ', the assembling jig 5 arranged between them.
The pressing body 18 such as a metal cylindrical pin or ball having a small radius of curvature with which the outer peripheral surfaces of the upper and lower side rails 8 and 9 of the combined piston ring 6 abutted against each other is attached in the circumferential direction corresponding to the inner diameter of the bore. A large number (11 in each example in each frame) are provided at appropriate intervals.

As an example of the pressing body 18, the fitting grooves 15 and 15 '(high height) into which the assembling jig 5 having the height dimension (H1) can be fitted are formed on the inner circumferential surface sides of the both frame bodies 4 and 4'. (Size = H2> H1) is formed by depression, and the pressing body 18 is provided in each of the fitting grooves 15 and 15 'so that a part of the convex surface such as a cylindrical pin or a ball is exposed. The pressing body 18 may be provided so as to be partially exposed on the inner circumferential surface of the frame body without providing the fitting grooves 15 and 15 '.

On the lower surface of the frame body 4 ′ that can be rotated on the support base 1, concave portions 19 are formed at appropriate places, and rolling bodies 20 such as metal balls are placed in the respective concave portions 19 and the frame body 4 ′ is formed. ′ Is configured so as to be able to rotate around the support shaft 17 with an extremely light force.

By pivotally attaching the frame body 4'to the support shaft 17 via a ball bearing, the frame body 4'can be horizontally rotated with a light force. Therefore, even if the rolling element 20 is omitted. good.

Reference numeral 21 is a tightening force detecting means for detecting a tightening force such as a load cell fixed to the outer surface of the flange 22 on the free end side opposite to the support shaft 17 in the other frame 4 ′, and is of the support base 1. An arm 24 is rotatably mounted on the upper surface of a bracket 23 so that the intermediate bar 25
Is movably mounted parallel to the upper surface of the support base 1 so as to move back and forth toward the tightening force detection means 21, and the intermediate bar
On the side opposite to the tightening force detection means 21 with 25 in between, an intermediate bar 25
Tightening means (26) is provided for pressing against the tightening force detection means (21).

One embodiment of the tightening means 26 is like a micrometer with length measuring means 26 ', as shown.
It is configured such that the rotatable frame body 4'is pressed by the spindle 27 of the tightening means 26 toward the fixed side frame body 4 to tighten the combined piston ring 6.

Further, reference numeral 28 denotes a rolling element such as a metal or ceramic ball interposed between the lower surface of the assembling jig 5 and the upper surface of the support 1, and a fluororesin sheet such as a tetrafluoroethylene resin. With the friction means, the friction reducing means 28 can transmit the vibration from the support base 1 described later to the built-in jig 5, while reducing the frictional force between the built-in jig 5 and the support base 1. It is what constitutes.

Further, a vibration exciter 29 for vertically rotating an unbalanced mass or the like that gives vibration to the support base 1 is fixed to the lower surface of the support base 1, and the vibration exciter 29 is used as a drive motor on the base 2. A vibrating means is provided which is operated at 30.

Incidentally, reference numeral 31 is a dynamic strain gauge for amplifying a signal from the load cell which is the tightening force detection means 21, reference numeral 32 is a display such as a digital voltmeter for digitally displaying the output signal from the dynamic strain gauge 31, the reference numeral Reference numeral 33 is a checker for controlling the drive time and stop time of the drive motor 30 and for storing the detected values on the recording paper when the tightened force detection values are measured a plurality of times for one combination type piston ring 6. It is a central controller having a function.

In this structure, the combined piston ring 6 as the object to be measured is previously fitted into the ring groove 14 of the assembling jig 5. At this time, the abutting portions of the upper and lower side rails 8 and 9 of the combination type piston ring 6 are set so as to be aligned with the position of the mark 34, which is stamped near the outer peripheral edge of the upper surface of the assembling jig 5.

On the other hand, the tightening force detection means 21 such as a load cell is set in an unloaded state, and the zero point calibration of the dynamic strain gauge 31 and the calibration of the display 32 are executed.

Then, the intermediate bar 25 on the support base 1 in the measuring device
Is flipped upward and the length measuring means 26 'in the tightening means 26 is set to a prescribed value in advance. This specified value means that the combination-type piston ring 6 is inserted into the cylinder bore of the engine, and the movable-side frame body 4 ′ is brought close to the fixed-side frame body 4 so that the gap size of the joint becomes a predetermined size. At the set position of the length measuring means 26 'when the intermediate bar 25 is inserted between the tightening force detecting means 21 at the free end of the movable frame 4'and the spindle 27 of the length measuring means 26'. is there.

Next, the movable side frame body 4'is opened, and the assembling jig 5 set as described above is arranged between the pair of frame bodies 4, 4'of the support base 1 in the measuring apparatus to reduce friction. Place on top.

At this time, if the handle 35 (shown by the alternate long and short dash line in FIG. 4) provided on the upper surface of the assembling jig 5 is used, the transportation becomes easy. In addition, the mark 34 in the assembling jig 5 is used as the pair of frame members.
It is adjusted so that it is located at 22 places of the flange portion of the frame body 4'of the free end side movable side of 4,4 '.

Next, at the hole on the upper surface of the support 1, the pivot pin of the operation lever 36
When 37 is inserted and set, and the outer peripheral surface of the movable side frame body 4'is pushed by the operation lever 36, the pair of frame bodies 4, 4 '
The outer periphery of the assembling jig 5 is fitted into the fitting grooves 15 and 15 'of, and the vertical rotation both side rails 8 and 9 of the combination type piston ring 6 are made by a large number of pressing bodies 18 on both frame bodies 4 and 4'. The outer peripheral surface of is pressed, and the side rails 8 and 9 are tightened so that the diameters thereof are reduced.

In this state, the arm 24 is lowered and set so that the intermediate bar 25 is located between the tightening force detection means 21 and the spindle 27 of the tightening means 26, and the force to the operation lever 26 is gently released and added. The operating lever 36 is removed from the support base 1 with all the force applied.

Next, when the switch of the central controller 33 is turned on and the drive motor 30 is operated for a predetermined time (about 10 seconds in the embodiment),
The support base 1 vibrates up and down by a vibrator 29 to reduce friction.
Vibration is also applied to the built-in jig 5 and further to the combination type piston ring 6 therethrough, and the positional relationship between the upper and lower side rails 8 and 9 and the spacer expander 7 in the ring groove 14 of the built-in jig 5. The parts are set in a predetermined posture, and the frictional force due to the contact between the pressing bodies 18 at the multiple positions on the left and right frame bodies and the outer peripheral surfaces of the side rails 8 and 9 is not biased. It will become familiar.

In this state, the value detected by the tightening force detection means 21 (usually the maximum value of the detected values) may be read.

It should be noted that the measurement may be performed in a vibrating state, or may be performed after appropriately vibrating for an appropriate time and after stopping the vibration. In addition, in consideration of the detection error, the measurement is performed a plurality of times, and if the detected value is within the range of the predetermined value, it is determined as a good product.

In this manner, the outer peripheral surfaces of the upper and lower side rails 8 and 9 of the combined piston ring 6 which is the object to be measured are predetermined in a state of being point-contacted or line-contacted by the pressing bodies 18 having a small radius of curvature. Since it is tightened to a diameter, frictional resistance due to contact can be extremely reduced.

Further, the difficulty of fitting at the contact portion between the spacer expander 7 and the upper and lower side rails 8 and 9 in the state of being assembled in the ring groove 14 of the assembling jig 5 is caused by the vibration applied to the support base 1. This can be solved by shaking the built-in jig 5 via the friction reducing means 28.

In particular, by interposing a friction reducing means 28 such as a ball between the support base 1 and the assembling jig 5, the left and right frame bodies 4 that vibrate,
By allowing relative movement between the 4'and the assembly jig 5, the outer peripheral surfaces of the upper and lower side rails 8,9 having a small thickness in the tightened state by the frame bodies 4,4 'and the pressing body. Eliminating the difficulty of contact with the surface of 18 and correcting the combination type piston ring 6 to a normal posture to eliminate the increase of frictional force due to unnatural contact between each part, and when measuring the tension of the piston ring You can get accurate results.

It goes without saying that various types of combination type piston rings 6 can be used as the object to be measured.

Further, the shape of the built-in jig 5 is such that the lower surface thereof has a friction reducing means.
It suffices to have a flat portion that can be brought into contact with 28 at an arbitrary position and have a ring groove formed on the outer periphery. The upper surface of the assembling jig 5 may be recessed to reduce the weight. Of.

[Brief description of drawings]

The drawings show an embodiment of the present invention. Fig. 1 is a plan view of a measuring device, Fig. 2 is a sectional view taken along line II-II of Fig. 1, and Fig. 3 is a perspective view of a main part of a combination type piston ring. 4 is a perspective view of the assembling jig, FIG. 5 is an enlarged cross-sectional view of an essential part of the assembling jig in which a combination type piston ring is incorporated, and FIG. 6 is an enlarged cross-sectional view of an essential part of FIG. 2 and FIG. FIG. 7 is a VII-VII view of FIG. 1. 1 ... Supporting base, 2 ... Base, 3 ... Spring, 4, 4 '
…… Frame, 5 …… Assembly jig, 6 …… Combination type piston ring, 7 …… Spacer expander, 8,9 …… Side rail, 14 …… Ring groove, 15,15 ′ …… Mating groove , 17 ……
Support shaft, 18 …… Pressing body, 19 Recessed portion, 20 …… Rolling body, 21 ……
Tightening force detection means, 25 ...... intermediate bar, 26 ...... tightening means,
26 '... measuring means, 27 ... spindle, 28 ... friction reducing means, 29 ... vibrator, 30 ... driving motor, 31 ... dynamic strain gauge,
32 ... Display, 33 ... Central control unit, 34 ... Mark, 35 ...
… Handle, 36… operating lever.

Claims (1)

[Scope of utility model registration request] 1. A disc-shaped assembling jig in which a combination type piston ring, which is an object to be measured, is fitted in a ring groove on the outer periphery, and a pair of a pair for tightening the assembling jig from the outer periphery and detecting the tightening force. The pair of frame bodies comprises a frame body and a support table on which the frame body is mounted, and a pressing body having a small radius of curvature that abuts the outer peripheral surface of the combination piston ring is attached to the pair of frame bodies. While providing a large number at appropriate intervals along the direction, one frame body of the pair of frame bodies is fixed to a support base, and the base end portion of the fixed frame body is connected to the base end portion of the other frame body. It is connected so as to be horizontally rotatable, and a friction reducing means is interposed between the lower surface of the assembling jig and the upper surface of the support base, and vibration is applied to the support base by vibrating means. And a piston ring tension measuring device.