JP3504582B2 - Measuring tool for inner diameter of annular groove - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an annular shape used, for example, in measuring the inner diameter of a thrust receiving groove provided in a cam cap that rotatably supports a cam shaft that drives an intake / exhaust valve in an engine in a cylinder head. The present invention relates to a tool for measuring the inner diameter of a groove.

[0002]

2. Description of the Related Art In a DOHC engine, for example, a camshaft 2 for driving intake and exhaust valves is rotatably supported by a cam cap 3 on a cylinder head 1 as shown in FIGS. That is, the cylinder head 1 is provided with a camshaft housing 1a having a semicircular supporting surface for supporting the camshaft 2, and the camshaft 2 is placed on the camshaft housing 1a to form the semicircular supporting surface. The cam shaft 2 is rotatably supported by the cylinder head 1 by attaching the cam cap 3 which it has. A thrust receiving collar 4 is integrally provided on the camshaft 2, and projecting portions 3a and 3a are provided on both sides of the cam cap 3 except for the central portion at the rear portion thereof. The thrust receiving collar 4 is provided on the projecting portions 3a and 3a. Is provided with thrust receiving grooves 5 and 5 into which the camshaft 2 is fitted and engaged, and the thrust receiving collar 4 of the camshaft 2 is fitted into and engaged with the thrust receiving grooves 5 and 5 to position the camshaft 2 in the thrust direction. ing.

By the way, the protruding portion 3a of the cam cap 3
The thrust receiving grooves 5 and 5 provided in 3a are finished by machining, but since machining errors are unavoidable, the inner diameters of the thrust receiving grooves 5 and 5 are slightly varied. . Therefore, after processing, it is necessary to individually measure whether the inner diameter dimensions of the thrust receiving grooves 5, 5 are within a predetermined tolerance.

Conventionally, in measuring the inner diameter of the thrust receiving grooves 5 and 5, the thrust receiving grooves 5 and 5 are the semicircular support surface of the shaft housing 1a of the head cylinder 1 and the cam cap 3.
Is located at the inner side of the camshaft support hole 6 having a semicircular support surface, and the thrust receiving grooves 5 and 5 are not continuous semicircles but intermittent shapes, and the cylinder head 1
As shown in FIG. 7, because it is necessary to measure with the cam cap 3 sub-assembled,
The touch probe 8 of the three-dimensional measuring device 7 is brought into contact with the inner diameters of the thrust receiving grooves 5 and 5, and the three-dimensional coordinate values of the inner diameters of the thrust receiving grooves 5 and 5 are taken in by the touch probe 7 as measured values, so that the thrust receiving The inner diameters of the grooves 5 and 5 are measured.

[0005]

However, in the conventional inner diameter dimension measurement, the inner diameter surfaces of the thrust receiving grooves 5 and 5 located on the inner side of the camshaft support hole 6 are traced so that Since the touch probe 8 of the coordinate measuring machine 7 has to be manually operated, there is a problem that it requires skill and takes a lot of time and effort. Therefore, a measuring tool that can easily measure whether or not the inner diameters of the thrust receiving grooves 5, 5 of the cam cap 3 are within a predetermined tolerance is desired.

The present invention has been made in view of the above circumstances, and provides an inner diameter dimension measuring tool for an annular groove capable of easily measuring whether or not the inner diameter dimension of the annular groove is within a predetermined tolerance. The purpose is to do.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is to measure the inner diameter of an annular groove located on the inner side of a hole. A housing integrally projecting forward from the end and having a through hole eccentric to the central axis line formed therethrough; a shaft rotatably fitted in the through hole of the housing; A handle fixed to the rear end of the shaft protruding from the through hole and a handle fixed to the tip of the shaft protruding from the through hole of the housing, and at the time of measurement, the distance from the central axis of the housing is the annular groove. It consists of a measuring element corresponding to the minimum value of the inner diameter dimension tolerance and a measuring gauge having a dead end measuring element corresponding to the maximum value.After inserting the front end of the housing into the hole, the measuring gauge is changed. The central axis of the grayed rotated as the center of rotation was to check through and blind the relative annular groove as the measuring element and stops measuring element of the measuring gauge.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 to 3, an inner diameter measuring tool for an annular groove according to the present invention includes a housing 11 having a stepped outer peripheral surface, and a shaft 12 rotatably provided on the housing 11. A handle 13 attached to the rear end of the shaft 12 and a measuring gauge 14 attached to the front end surface of the shaft 12 are provided.

The housing 11 has a small-diameter front end which is fitted into a camshaft support hole 6 formed of a semicircular support surface of the shaft housing 1a of the head cylinder 1 and a semicircular support surface of the cam cap 3. The large-diameter rear end portion 18 in which the portion 15 and the outer peripheral surface are knurled, and two-color marking engraved lines, for example, a light blue engraved line 16 and a red engraved line 17, are formed at equidistant positions on the circumference. Have. In addition, light blue engraved line 1
6 is formed at a position where a ball plunger 20 to be described later is screwed, and the red engraved lines 17 are formed 180 ° apart from that. A through hole 19 for inserting the shaft 12 is formed in the housing 11 so as to be eccentric to the central axis by a predetermined distance.

The shaft 12 is rotatably fitted in a through hole 19 of the housing 11 and is placed in a predetermined rotational position with respect to the housing 11 by a ball plunger 20 screwed into a large-diameter rear end portion 18 of the housing 11. It is locked.

The handle 13 has a set screw 21 at the rear end of the shaft 12 protruding from the through hole 19 of the housing 11.
Is fixed at a predetermined rotation position with respect to the shaft 12. The handle 13 has a knurled outer peripheral surface, and has two-color marking engraving lines, for example, red engraving lines 22.
And light blue engraved lines 23 are formed at evenly distributed positions on the circumference.
The red engraved line 22 is formed at a position where the set screw 21 is screwed in, and the light blue engraved line 23 is formed at an interval of 180 ° from it.

The measuring gauge 14 is fixed to the tip end surface of the shaft 12 with a bolt 24 at a predetermined rotational position with respect to the shaft 12. As shown in FIG. 3, the measuring gauge 14 is formed in a fan shape that requires the shaft 12, and has hump-shaped measuring elements 25 and 26 at both ends of its arcuate peripheral surface.
And a hump-shaped dead end measuring element 27 is provided at the center of the circumferential surface of the circular arc. The distances from the central axis of the housing 11 do not match between the through-measuring elements 25 and 26 and the dead-end measuring element 27. That is, the distance between the through-measuring elements 25 and 26 from the central axis of the housing 11 corresponds to the minimum value of the inner diameter dimension tolerance of the thrust receiving groove 5 of the cam cap 3, and the dead-end measuring element 27 from the central axis of the housing 11. The distance corresponds to the maximum inner diameter dimension tolerance of the thrust receiving groove 5 of the cam cap 3.

Next, the thrust receiving groove 5 of the cam cap 3 in the state where the cylinder head 1 and the cam cap 3 are sub-assembled by the inner diameter dimension measuring tool of the annular groove according to the present invention.
A case of measuring the inner diameter dimension of No. 5 will be described. As shown in FIG. 4 (a), the tool for measuring the inner diameter of the annular groove according to the present invention is formed on the handle 13 and the light blue engraved line 16 formed on the large-diameter rear end portion 18 of the housing 11 in the initial state. The red engraved lines 22 aligned with each other are aligned, and these are oriented in the horizontal left and right directions. In this state, the housing 11
The shaft 12 is horizontally eccentric with respect to the central axis of the.

First, the small-diameter front end portion 15 of the housing 11 is fitted into the camshaft support hole 6, and the measuring gauge 14 is positioned so as to face the thrust receiving grooves 5 and 5 of the cam cap 3. At this time, the small-diameter front end portion 15 of the housing 11
Is the light blue engraved line 16 and the red engraved line 17 of the large-diameter rear end portion 18.
Are horizontally inserted into the camshaft support holes 6 in the horizontal direction. As a result, the small-diameter front end portion 15 of the housing 11 can be fitted into the camshaft support hole 6 so that the measurement gauge 14 does not interfere with the camshaft support hole 6. At this time, as shown in FIG. 4A, the measurement gauge 14 is in a state where the dead end probe 27 is positioned in the horizontal direction with respect to the central axis of the housing 11.

Next, from the state shown in FIG. 4A, the housing 11 is rotated counterclockwise so that the light blue marking line 16 and the red marking line 17 of the large-diameter rear end portion 18 are oriented vertically upward and downward.
The shaft 12 is rotated by 0 °, and the shaft 12 is rotated by 90 ° in the counterclockwise direction with the central axis of the housing 11 as the center of rotation in synchronization with the rotation of the housing 11. As a result, the shaft 1
Consistent with the rotation of 2, the measuring gauge 14 rotates 90 ° counterclockwise about the central axis of the housing 11. As a result, the measurement gauge 14 is in a state in which the dead end probe 27 is positioned vertically upward with respect to the central axis of the housing 11, as shown in FIG.

Next, from the state shown in FIG. 4B, the handle 13 is attached to the housing 11 so that the light blue engraved line 23 of the handle 13 and the light blue engraved line 16 of the large-diameter rear end portion 18 of the housing 11 coincide with each other. And the shaft 12 is rotated 180 ° relative to the housing 11 in accordance with the rotation of the handle 13. As a result, the measurement gauge 14 rotates 180 ° with respect to the housing 11 in synchronization with the rotation of the shaft 12. As a result, the measurement gauge 14
As shown in FIG. 4 (c), the dead end probe 27 is positioned vertically below the central axis of the housing 11.

Next, from the state shown in FIG. 4C, the housing 11 is rotated 90 ° in the clockwise and counterclockwise directions, and the shaft 12 coincides with the rotation of the housing 11.
Is rotated 90 ° clockwise and counterclockwise about the center axis of the housing 11. As a result, the measurement gauge 14 rotates 90 ° clockwise and counterclockwise about the central axis of the housing 11 in synchronization with the rotation of the shaft 12. When the measuring gauge 14 rotates,
As shown by the phantom chain line in FIG. 4C, the measuring gauges 25 and 26 pass through the thrust receiving grooves 5 and 5 of the cam cap 3 as shown in the measuring gauge 14, and the dead measuring tip 27 of the measuring gauge 14 corresponds to the cam cap. By stopping at the thrust receiving grooves 5 and 5 of No. 3, it can be measured that the inner diameter dimension of the thrust receiving grooves 5 and 5 of the cam cap 3 is within a predetermined tolerance. When the measuring gauge 14 is rotated, the measuring elements 25, 2
If 6 stops in the thrust receiving grooves 5 and 5 of the cam cap 3, it can be measured that the inner diameter dimension of the thrust receiving grooves 5 and 5 is less than or equal to a predetermined tolerance. By passing the thrust receiving grooves 5 and 5 of No. 3, it can be measured that the inner diameter dimension of the thrust receiving grooves 5 and 5 is more than a predetermined tolerance.

According to the tool for measuring the inner diameter of the annular groove according to the present invention, with the cylinder head 1 and the cam cap 3 sub-assembled, the cam shaft support hole 6 is fitted as a guide, and after the fitting, the eccentricity is obtained. The thrust receiving groove 5 of the cam cap 3 is made by a simple operation such as rotating only the measured gauge 14 with the central axis of the housing 11 as the center of rotation and checking the passage and stop of the tracing stylus 25, 26 and the stylus stylus 27. It is possible to measure whether or not the inner diameter dimensions of 5 and 5 are within a predetermined tolerance.

In the above embodiments, the suitability of the inner diameter of the thrust receiving grooves 5, 5 of the cam cap 3 mounted on the cylinder head of the engine is measured. However, the inner diameter of the annular groove according to the present invention is measured. The measuring tool can be applied to other than the thrust receiving grooves 5 and 5 of the cam cap 3.

[0021]

As described above, according to the inner diameter measuring instrument for an annular groove of the present invention, it is possible to measure whether the inner diameter of the annular groove is within a predetermined tolerance by a simple operation. Therefore, the suitability of the inner diameter of the annular groove can be easily measured in a short time, and the efficiency of the measurement work can be improved.
Moreover, the inner diameter dimension measuring tool of the annular groove according to the present invention has an excellent effect that it can be manufactured at low cost because its structure is very simple.

[Brief description of drawings]

FIG. 1 is a plan view of an inner diameter dimension measuring tool for an annular groove according to the present invention.

FIG. 2 is a vertical cross-sectional view of a tool for measuring the inner diameter of an annular groove according to the present invention.

FIG. 3 is a left side view of an inner diameter dimension measuring tool for an annular groove according to the present invention.

FIG. 4 is an explanatory view showing a measuring operation of the inner diameter dimension measuring tool of the annular groove according to the present invention.

FIG. 5 is a vertical cross-sectional view showing a support structure for a camshaft.

6 is a diagram viewed from an arrow A in FIG.

FIG. 7 is an explanatory diagram showing a conventional method for measuring a thrust groove of a camshaft by three-dimensional measurement.

[Explanation of symbols]

1 cylinder bed 2 camshaft 3 cam cap 4 Thrust receiving tsuba 5 Thrust receiving groove 6 Camshaft support holes 11 housing 12 shafts 13 handle 14 Measuring gauge 15 Small diameter front end 16 marking line (light blue line) 17 Mark engraving line (red engraving line) 18 Large diameter rear end 22 Mark engraved line (red engraved line) 23 Mark engraved line (light blue engraved line) 25 ways 26 ways 27 Stopper

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Claims (2)

(57) [Claims] 1. A method for measuring an inner diameter of an annular groove located on the far side of a hole, wherein a front end portion fitted into the hole is integrally formed by projecting forward from a rear end portion, and A housing having a through hole formed eccentrically with respect to the central axis, a shaft rotatably fitted in the through hole of the housing, and fixed to a rear end of the shaft protruding from the through hole of the housing. Fixed to the tip of the shaft protruding from the through hole of the housing, and at the time of measurement, the distance from the center axis of the housing corresponds to the minimum inner diameter dimension tolerance of the annular groove. A measurement gauge having a dead end corresponding to the value, and after inserting the front end of the housing into the hole, rotate the measurement gauge about the central axis of the housing as a rotation center. Nomination measuring instrument of the annular groove, characterized in that so as to check through and blind the relative annular groove as the measuring element and stops the gauge constant gauge. 2. The annular groove inner diameter measuring tool according to claim 1, wherein the shaft is locked at a predetermined rotational position with respect to the housing by an appropriate locking means.