JPH07128005A - Measuring instrument with unfixed measuring probe - Google Patents

Abstract

PURPOSE:To provide a measuring instrument which can measure inner and outer diameter dimensions of an object to be measured accurately even if a groove part such as a gear groove exists at a position where the center deviates from that of a measuring probe on the inner/outer-periphery surfaces of the object with a cylindrical shape. CONSTITUTION:The tips of a plurality of measuring probes 7A which are arranged radially and are retained at a substrate so that they can move directly in the radius direction of an object 14 to be measured with a cylindrical shape are allowed to contact the inner-periphery surface of the object 14, thus measuring the inner-diameter dimensions of the object 14 according to the amount of travel in the radius direction of the measurement probes 7A. The non-fixed type measuring probes 7A have a head part 7c which can be rocked in the peripheral direction of the inner-periphery surface of the object 14 at its tip. Even if a groove part where the center deviates in the peripheral direction from that of the measurement probes 7A exists on the inner- periphery surface of the object, the head part 7c of the measuring probes 7A rock in peripheral direction and positively contact both wall surfaces constituting the above groove, thus preventing the move of the measuring probes 7A in the radius direction from being regulated halfway.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measuring instrument for measuring an inner diameter or an outer diameter of a cylindrical part, and is particularly suitable for measuring inner and outer diameters of inner and outer gears and inner and outer splines. The present invention relates to a measuring instrument with a non-fixed type probe.

[0002]

2. Description of the Related Art A three-point type inner diameter measuring device (three-point type micrometer) is used to precisely measure the inner diameter of a cylindrical part such as a cylinder on which a piston slides. Is used. For example, the three-point micrometer disclosed in Japanese Utility Model Publication No. 61-5 has three legs 91, 92, 9 as shown in FIG.
The axes ga, gb, gb ′ of the three axes are 120
A fixed tripod body 90 arranged at an angle of degrees, and a fixed rod 94 as a measuring element screwed into the two legs 92 and 93,
95 and a micrometer 96 screwed to the other leg 91.
And a measuring rod 97 as a probe attached to the tip of the micrometer 96. Fixed rod 9
4, 95, and the measuring rod 97 are prepared with various known lengths, and are used after being replaced according to the size of the inner diameter of the object to be measured. In the fixed rods 94 and 95, the intersection point g
The distance from to the tip is always the same.

When measuring the inner diameter of a cylindrical part using this three-point micrometer, first, the fixing rods 94, 95 are used.
The tip of the abutment on the inner peripheral surface of the object to be measured. Next, the micrometer 96 is rotated to bring the tip of the measuring rod 97 into contact with the inner peripheral surface of the object to be measured. By reading the scale of the micrometer at that time, the distance from the intersection point g to the tip of the measuring rod 97 can be known. Then, using this value and the distance from the intersection point g to the tip of the fixed rod 94 (95), 3
By using the square theorem or the like, the inner diameter of the object to be measured can be obtained.

[0004]

However, when the above-mentioned conventional three-point type micrometer is used to measure, for example, the inner diameter of the internal gear, the following inconvenience may occur. That is, in the above conventional three-point micrometer,
The fixed rods 94 and 95 and the measuring rod 97 as the measuring element cannot swing in the circumferential direction. For this reason, since the product error of the internal gear, for example, the pitch error, is large, as shown in FIG.
When the center of the measurement rod is displaced in the circumferential direction, the tip of the measuring rod 97 comes into contact with one of the tooth flanks of the tooth groove 98, and the outward movement in the radial direction is restricted. As a result, in order to accurately measure the inner diameter dimension (maximum dimension) of the internal gear, the measuring rod 97 originally has to move further outward in the radial direction, but it stops in the middle of the measurement rod 97. It will not be possible to obtain accurate measured values.

The present invention has been made in view of the above circumstances and has a groove portion such as a tooth groove on the inner and outer peripheral surfaces of an object to be measured having a cylindrical shape, and the center of the groove portion and the center of the probe are Even if the
It is a technical problem to be solved to provide a measuring instrument with a non-fixed type stylus capable of measuring an outer diameter dimension.

[0006]

Means for Solving the Problems The non-fixed type measuring device with a stylus according to the present invention for solving the above-mentioned problems is arranged radially.
And, the tips of a plurality of measuring elements held on the base body so as to be linearly movable in the radial direction of the measured object having a cylindrical shape are brought into contact with the inner peripheral surface or the outer peripheral surface of the measured object, A measuring instrument for measuring an inner diameter or an outer diameter of an object to be measured according to a moving amount in a radial direction, wherein the probe is a swing of an inner peripheral surface or an outer peripheral surface of the object to be measured in a circumferential direction. It is characterized by having a head capable of

[0007]

The non-fixed type measuring instrument with a measuring head according to the present invention has a head which abuts on the inner and outer peripheral surfaces of the measuring object at the tip of the measuring element held by the base body so as to be linearly movable in the radial direction. The part is held swingably in the circumferential direction of the inner and outer peripheral surfaces. For this reason,
When there is a groove portion such as a tooth groove whose center is displaced from the center of the probe in the circumferential direction on the inner and outer peripheral surfaces of the object to be measured, the head contacting one of the wall surfaces forming the groove portion The probe moves linearly in the radial direction while being guided by the wall surface and swinging in the circumferential direction.
As a result, the head of the tracing stylus is surely brought into contact with both wall surfaces forming the groove, and the radial movement of the tracing stylus is regulated halfway by coming into contact with one of the walls forming the groove. Never.

Therefore, even if the inner and outer peripheral surfaces of the object to be measured have a groove portion such as a tooth groove whose center is displaced from the center of the probe in the circumferential direction, the inner and outer diameter dimensions can be measured reliably. Is possible.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The non-fixed type measuring device with a stylus of the present invention will be described in detail below with reference to the accompanying drawings. (First Embodiment) The measuring instrument with a non-fixed type probe according to this embodiment shown in FIGS. 1 to 3 is for measuring the inner diameter of a cylindrical part.

As shown in FIG. 1, a ring-shaped mounting table 2 on which an object to be measured is placed is fixed on the upper surface of a substantially cylindrical base 1 having a central through hole 1a, and the central through hole 1a.
A cylinder 3 having a housing recess 3a having a circular cross section and a shaft hole 3b is fitted and fixed to the upper part of the. Inside the shaft hole 3b of the cylinder 3, a center shaft 4 having a frustoconical head portion 4a on the upper end side and a ring portion 4b fitted on the lower end side can slide via a bearing 5. Has been inserted into. The head portion 4a of the center shaft 4
Is accommodated in the accommodating recess 3a of the cylinder 3, and an operation rod 4d protruding upward from the cylinder 3 is projectingly provided on the upper end surface thereof. The center shaft 4 has a cylinder 3
Due to this, the ring 4c whose upward movement is restricted is loosely fitted. The center shaft 4 is urged downward by the first spring 6 whose one end is in contact with the ring portion 4b of the center shaft 4 and whose other end is in contact with the ring 4c loosely fitted to the center shaft 4. ing.

On the annular side wall surface 3c forming the recess 3a of the cylinder 3, as shown in FIG. 2, at positions which are arranged at an angle of 120 degrees on the horizontal plane and are divided into three equal parts in the circumferential direction, Three through holes 3d are formed so as to face the centering direction of the cylinder 3. In each of the through holes 3d, two non-fixed type probe 7A, 7A and one fixed type probe 7 are provided.
B and B are movably inserted. Each probe 7A, 7
A and 7B are biased in the centripetal direction of the cylinder 3 by the second spring 8, respectively. Then, each measuring element 7A, 7
The base end faces of A and 7B (the centripetal side end face of the cylinder 3) are in contact with the tapered side faces of the head portion 4a of the center shaft 4.

As shown in FIG. 3, a concave portion 7a is provided on the tip surface of the non-fixed type probe 7A, and a spherical head portion 7c supported by a pin 7b is accommodated in the concave portion 7a. A through hole having a hole diameter larger than the outer diameter of the pin 7b passing through the center of the head portion 7c is bored in the head portion 7c, and the pin 7b is inserted into the through hole. Further, the upper and lower end surfaces of the head 7c are in contact with the upper and lower wall surfaces of the recess 7a, and the head 7c
The vertical movement of the is restricted. As a result, the head 7c is held at the tip of the non-fixed probe 7A so that the head 7c can swing in the circumferential direction along the inner peripheral surface of the object to be measured. On the other hand, as shown in FIG. 2, a head 7d having an outer diameter equivalent to that of the head 7c of the non-fixed probe 7A is integrally formed at the tip of the fixed probe 7B. The non-fixed type measuring element 7A and the fixed type measuring element 7B are prepared in various lengths according to the size of the inner diameter of the object to be measured. The outer diameters of the head 7c of the non-fixed type probe 7A and the head 7d of the fixed type probe 7B also depend on the size of a groove portion such as a tooth groove formed on the inner peripheral surface of the object to be measured. , Prepare various sizes.

A side hole 1b communicating with the central through hole 1a is formed on the side surface of the base 1, and a holding tool 9 for holding an indicator 10 described later is fitted and fixed to the side hole 1b by a bolt. Has been done. The holder 9 has a large diameter hole 9a.
And the small-diameter hole 9b are coaxially penetrated, and the indicator 10 is inserted and held in the large-diameter hole 9a.
Plunger 11 is fitted in b so as to be linearly movable. The plunger 11 is urged by the third spring 12 toward the center through hole 1a of the base 1, that is, in the leftward direction in FIG. A hinge lever 13 is swingably supported on the base 1. One end of the hinge lever 13 contacts the lower end surface of the center shaft 4 and the other end of the hinge lever 13 contacts the end surface of the plunger 11. Abutting.

The biasing force of the first spring 6 that biases the center shaft 4 downward is determined by the contact points 7A, 7A, 7
Second spring 8 for biasing B in the centripetal direction, and plunger 1.
1 is set to be much larger than the urging force of the third spring 12 for urging the method 1 in FIG. Further, the head portion 4a of the center shaft 4 is in contact with the cylinder 3, whereby the maximum downward movement of the center shaft 4 is restricted.

The inner diameter of the inner spline 14 was measured as follows using the non-fixed type measuring instrument with a stylus having the above-mentioned structure. As shown in the partial cross-sectional view of FIG. 4, three tooth groove portions 14A having a plurality of tooth grooves 14a are arranged and formed on the inner peripheral surface of the inner spline 14 at three equally divided positions. There is. In addition, each measuring element 7A, 7A, 7B
Has a length corresponding to the inner diameter of the inner spline 14. The outer diameters of the head portion 7c of the non-fixed type measuring element 7A and the head portion 7d of the fixed type measuring element 7B are selected to have a size corresponding to the size of the tooth groove 14a of the inner spline 14.

When setting the inner spline 14 as the object to be measured in the measuring instrument, first, with the fingers or the like, the operating rod 4d of the center shaft 4 is resisted against the urging force of the first spring 6.
Is pulled upward and each probe 7 is pressed by the urging force of the second spring 8.
A, 7A and 7B are retracted in the centripetal direction.
Then, in this state, the mounting table 2 is aligned while circumferentially aligning the inner spline 14 so that the tooth groove portions 14A divided into three equal parts face the respective tracing styluses 7A, 7A, 7B.
After placing the finger on the operating rod 4d of the center shaft 4, the center shaft 4 is returned downward by the urging force of the first spring 6. Along with this, the head portions 4a of the center shaft 4 are pressed by the frustoconical head portion 4a, and the tracing stylus 7A, 7A, 7B moves radially outward of the inner spline 14 against the biasing force of the second spring 8. And each probe 7
The heads 7c, 7c, 7d of A, 7A, 7B contact the inner peripheral surface of the inner spline 14. These measuring elements 7A, 7A, 7
The amount of movement of B is the center shaft 4 and the hinge lever 13.
Also, it is transmitted to the indicator 10 via the plunger 11 and displayed as a measurement value on the indicator 10.

If the center of each of the tracing stylus 7A, 7A, 7B and the center of the tooth groove 14a with which the head portion 7c, 7c, 7d is accommodated and abutted are displaced from each other in the circumferential direction, the fixed type The head portion 7d of the probe 7B is the tooth groove portion 1 of the inner spline 14.
4A fits in one tooth groove 14a,
The inner spline 14 rotates in the circumferential direction so that the head portion 7d comes into contact with both tooth surfaces forming 4a. As a result, the center of the fixed probe 7B and the center of the tooth space 14a coincide with each other. At this time, even if the centers of the non-fixed type measuring heads 7A, 7A and the centers of the tooth spaces 14a that these measuring points 7A, 7A face are deviated in the circumferential direction, the head of the non-fixed type measuring point 7A. Since 7c is allowed to move horizontally by a set clearance with the pin 7b, the head portion 7c which is in contact with one of the tooth surfaces forming the tooth groove 14a is guided by the wall surface and swings in the circumferential direction. The non-fixed type probe 7A moves outward in the radial direction while moving. As a result, as shown in FIG. 5, the head portion 7c of the non-fixed type measuring element 7A is surely brought into contact with both tooth surfaces forming the tooth groove 14a, and the non-fixed type measuring element 7A is radially outward. Is not regulated on the way by contacting one of the tooth surfaces constituting the tooth groove 14a. In addition, in the state of FIG. 5, the outer peripheral surface of the head portion 7c abuts on both tooth surfaces of the tooth groove 14a, and
It contacts the side wall surface 7d of the concave portion 7a of A, and the fixed probe 7A and the head portion 7c are hardly displaced relative to each other in the radial direction. Therefore, the measurement error due to the existence of the setting gap between the through hole of the head portion 7c and the pin 7b can be neglected and is acceptable.

Therefore, the tooth groove 14 of the inner spline 14
Even if there is a pitch error in a and the centers of the heads 7c, 7c, 7d of the tracing stylus 7A, 7A, 7B and the center of the tooth space 14a are displaced in the circumferential direction, the non-fixed measurement of this embodiment is performed. According to the inner diameter measuring device with a child, the inner diameter dimension (maximum dimension) of the inner spline 14 can be accurately measured. (Second Embodiment) A non-fixed measuring element with a stylus according to this embodiment shown in FIGS. 6 and 7 is for measuring the outer diameter of a cylindrical part.

As shown in FIG. 6, on the upper surface of the base 15 having a central through hole 15a, a mounting table 16 for mounting an object to be measured is formed while forming a housing recess 17 for housing the center shaft 18 and the like. It is fixed by tightening bolts. In addition, an insertion hole 16a through which an operation rod 18d of a center shaft 18, which will be described later, can be inserted is provided at the center of the mounting table 16. A center shaft 18 having a truncated cone-shaped head portion 18a on the upper end side and a ring portion 18b fitted on the lower end side is slidable via a bearing 19 in the central through hole 15a of the base 15. Has been inserted into. The head portion 18a of the center shaft 18 is housed in the housing recess 17, and an operation rod 18d protruding upward from the mounting table 16 is provided on the upper end surface of the head portion 18a. On the center shaft 18, a ring 18c whose upward movement is restricted by the base 15 is loosely fitted. The center shaft 18 is
The first spring 20 has one end abutting on the ring portion 18b and the other end abutting on the ring 18c loosely fitted to the center shaft 18, and is urged downward.

The side wall surface of the base 15 is arranged at an angle of 120 degrees on the horizontal plane and is divided into three equal parts in the circumferential direction.
Three opening portions 21 communicating with each other are formed, and three slide tables 22 are inserted from the respective opening portions 21 into the accommodation recesses 17, respectively. Note that FIG. 6 shows only one of the three slide tables 22.
Each slide table 22 has a bearing 24 on a table base 23 fixed to the side wall surface of the base 15 by bolting.
Are held so as to be movable in the horizontal direction. In addition, each table base 23 and each slide table 22
The second springs 26 are respectively interposed between the projecting pieces 25 protrudingly provided on the slide table 22.
The springs 26 are biased in the centripetal direction of the base 15 (in the slide table 22 shown in FIG. 6, leftward in FIG. 6). The centripetal side end surface of each slide table 22 (the left end surface of FIG. 6 in the slide table 22 shown in FIG. 6) is in contact with the tapered side surface of the head portion 18 a of the center shaft 18.

A connecting rod 27 is attached to each slide table 22.
The plates 28 are connected to each other via. Then, the non-fixed type probe 29A is screwed onto the centripetal side end surface of each of the two plates 28 out of the three plates 28. Further, a fixed probe 29B is screwed onto the center side of the remaining one plate 28. Thereby, each of the tracing stylus 29A, 29A, 29B is
On the horizontal plane, they are arranged at an angle of 120 degrees and are equally divided into three in the circumferential direction, and their ends are arranged so as to face the centripetal direction of the base 15. In addition, as the slide table 22 moves in the horizontal direction,
Each of the tracing stylus 29A, 29A, 29B is also movable in the horizontal direction synchronously via the connecting rod 27 and the plate 28.

At the tip of the non-fixed type probe 29A,
With the same configuration as the non-fixed type probe 7A of the first embodiment, the spherical head 29c is held so as to be able to swing in the circumferential direction along the outer peripheral surface of the measured object. Also,
The head 2 of the non-fixed type probe 29A is also attached to the tip of the fixed type probe 29B, similarly to the fixed type probe 7B of the first embodiment.
A head portion 29d having an outer diameter equivalent to that of 9c is integrally formed. The non-fixed type measuring element 29A and the fixed type measuring element 29B are prepared in various lengths according to the size of the outer diameter of the object to be measured, as in the first embodiment. The outer diameters of the head portion 29c of the non-fixed type measuring element 29A and the head portion 29d of the fixed type measuring element 29B are also determined according to the size of a groove portion such as a tooth groove formed on the outer peripheral surface of the object to be measured. Prepare items of various sizes.

A base 30 having a central hole 30a through which the center shaft 18 is inserted is fixed to the lower end surface of the base 15, and the lower end surface of the base 30 is located at a position close to the central hole 30a. The holder 31 is fixed. A hinge lever 33 is attached to a support pin 32 protruding from the holder 31.
Is supported at the center thereof, and the hinge lever 33 is rotatable around the support pin 32. One end of the hinge lever 33 is in contact with the lower end surface of the center shaft 18, and the other end of the hinge lever 33 is in contact with the lower end surface of a plunger 34 connected to an indicator 35 described later. The plunger 34 can be inserted into a hole 30b penetrating the base 30, and the indicator 35 is held by the base 30 via a holding base 36.

The urging force of the second spring 26 for urging the slide tables 22 in the centripetal direction is set to be much larger than the urging force of the first spring 20 for urging the center shaft 18 downward. Has been done. Further, the centering side end surface of each slide table 22 contacts the shaft portion of the center shaft 18, whereby the maximum movement of the slide table 22 in the centering direction is restricted.

The outer diameter of the outer spline 37 was measured as follows using the non-fixed type measuring instrument with a stylus of the present embodiment having the above-mentioned structure. Note that, as shown in the partial cross-sectional view of FIG. 7, three tooth groove portions 37A having a plurality of tooth grooves 37a are arranged and formed on the outer peripheral surface of the outer spline 37 in three equally divided positions. . In addition, each probe 29A, 29A,
29B has a length corresponding to the outer diameter of the outer spline 37. Furthermore, the outer diameters of the head portion 29c of the non-fixed type probe 29A and the head portion 29d of the fixed type probe 29B are
The size corresponding to the size of the tooth groove 37a of the outer spline 37 was selected.

When the outer spline 37 as the object to be measured is set on the measuring device, first, the operating rod 18d of the center shaft 18 is pushed downward against the urging force of the second spring 26 with a finger or the like. As a result, each slide table 22 moves in the radial direction while slidingly contacting the tapered side surface of the head portion 18a of the center shaft 18. Along with the movement of the slide table 22, each of the tracing stylus 29A, 29A, 29B also moves in the radial direction via the connecting rod 27 and the plate 28. In this way, each probe 2
9A, 29A, 29B are expanded in the radial direction so as not to interfere with the outer spline 37, and the outer spline 37 is set to 3
The tooth spaces 37A, which are equally divided, are
After being placed on the mounting table 16 while being aligned in the circumferential direction so as to face the 29B, the fingers and the like are separated from the operating rod 18d of the center shaft 18. As a result, the slide table 22 and the tracing stylus 29A, 29A, 29B are synchronously moved by the urging force of the second spring 26 in the centripetal direction, that is, inward in the radial direction of the outer spline 37,
Heads 29c, 29 of each of the tracing stylus 29A, 29A, 29B
c and 29d contact the outer peripheral surface of the outer spline 37. The slide tables 22 and the tracing stylus 29A, 29
The movement amounts of A and 29B are transmitted to the indicator 35 via the center shaft 18, the hinge lever 33 and the plunger 34, and displayed on the indicator 35 as a measured value.

Here, each of the tracing stylus 29A, 29A, 29B
When the center of each of the heads 29c, 29c, and 29d is deviated in the circumferential direction from the center of the tooth groove 37a in which the heads 29c, 29c, and 29d are housed and abutted, each of the tracing stylus 29A, Heads 29c, 29c, 29d of 29A, 29B
Can be reliably brought into contact with both tooth surfaces of the tooth groove 37a.

Therefore, the tooth groove 37 of the outer spline 37 is
a has a pitch error, and each of the tracing stylus 29A, 29A, 29
Even if the centers of the heads 29c, 29c, 29d of B and the center of the tooth groove 37a are deviated from each other in the circumferential direction, according to the non-fixed type outer diameter measuring device with the contact point, the outer spline 14
The outer diameter dimension of can be accurately measured. In addition, in the non-fixed type probe 7A (29A) of the above embodiment, the pin 7b is inserted through the through hole formed in the spherical head portion 7c with the setting gap provided. In the non-fixed type probe, it suffices that the head is held so as to be swingable in the circumferential direction of the inner and outer peripheral surfaces of the object to be measured. Therefore, it is possible to form a long hole along the circumferential direction of the inner and outer peripheral surfaces of the object to be measured and to insert the pin into the long hole.

Further, in the above embodiment, an example in which the number of the measuring heads is three, the number of the non-fixed type measuring elements is two, and the one of the fixed type measuring elements is one is shown. The number of fixed type stylus is not particularly limited. However, it is preferable that the number of the fixed stylus is one at most.

[0030]

As described in detail above, the non-fixed type measuring instrument with a measuring element according to the present invention is provided with a measuring element attached to the tip of the measuring element held on the base body so as to be linearly movable in the radial direction of the measuring object. Since the head that abuts the inner and outer peripheral surfaces is held so that it can swing in the circumferential direction of the inner and outer peripheral surfaces, its center is the center of the probe on the inner and outer peripheral surfaces of the object to be measured. Even if there is a groove portion such as a tooth groove deviated in the circumferential direction, the inner and outer diameter dimensions can be reliably measured by moving the head portion in the circumferential direction.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the overall configuration of an inner diameter measuring instrument with a non-fixing type probe according to a first embodiment.

FIG. 2 is a partial cross-sectional view showing a main part of the inner diameter measuring instrument and explaining the arrangement of the tracing stylus.

FIG. 3 is a partial cross-sectional view illustrating a main part of the inner diameter measuring device and illustrating a structure of a non-fixed type probe.

FIG. 4 is a partial sectional view showing the shape of an inner spline whose inner diameter is measured by the inner diameter measuring device.

FIG. 5 is a partial cross-sectional view illustrating a state in which the head of the non-fixed type probe of the inner diameter measuring device contacts the tooth groove of the inner spline.

FIG. 6 is a cross-sectional view showing an overall configuration of an outer diameter measuring instrument with a non-fixed type probe according to a second embodiment.

FIG. 7 is an explanatory view showing a state in which a probe of the outer diameter measuring device is in contact with an outer peripheral surface of an outer spline.

FIG. 8 is a front view showing the overall configuration of a conventional inner diameter measuring instrument.

FIG. 9 is a partial cross-sectional view illustrating a state in which a conventional fixed stylus contacts the tooth space.

[Explanation of symbols]

7A and 29A are non-fixed stylus, 7c and 29c are heads,
Reference numeral 14 is an inner spline as an object to be measured, and 37 is an outer spline as an object to be measured.

Claims (1)

[Claims] 1. The tips of a plurality of measuring elements radially arranged and held by a base body so as to be linearly movable in a radial direction of an object to be measured having a cylindrical shape, the inner peripheral surface of the object to be measured or A measuring device which is brought into contact with an outer peripheral surface and measures an inner diameter or an outer diameter dimension of the measured object according to a radial movement amount of the measured element, wherein the measuring element is an inner circumference of the measured object. A non-fixed type measuring instrument with a stylus, which has a head at the tip thereof, which allows the surface or the outer peripheral surface to swing in the circumferential direction.