JPH07103855A - Apparatus for measuring shift of tooth space - Google Patents

Abstract

PURPOSE:To effect highly accurate measurement by preventing the shifted contact of a probe when the shift of a tooth space is measured thereby sustaining the relative pressing force between the probe and a gear to be measured at a constant level. CONSTITUTION:A work supporting jig 2 is mounted rotatably on a base 1a and a measuring unit 4, comprising a measuring probe 5 provided rockingly, a member 7 for pressing the measuring probe against a work, a member 8 for detecting the pressing force thereof, and a member 9 for detecting the displacement of the measuring probe, is disposed movably in vertical and horizontal directions. A member 11 for detecting the height of the measuring unit from the base is also provided. The measuring unit 4 is moved laterally and the measuring probe 5 is fitted in the tooth space of a work W which is then rotated to butt against the opposite sides of the tooth. The measuring unit 4 is fed furthermore under that state and when the pressing force of the measuring probe 5 is settled, the displacement thereof is read out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring tooth groove runout relating to gear error.

[0002]

2. Description of the Related Art Tooth groove runout relating to the error of a bevel gear is
As shown in FIG. 2A, when a contact piece O such as a ball is brought into contact with both tooth flanks of a tooth groove at an average cone distance in the vicinity of a pitch circle P, it is represented by a maximum difference in position in a direction N perpendicular to the cone. Be done. That is, for each tooth groove, it is obtained by measuring the variation of the distance R from the central axis of the gear to the contact piece O. Conventionally, the measurement of the runout of the tooth space is performed using a coordinate measuring machine or a measuring machine dedicated to gears, but these measuring machines are expensive, and because the gear to be measured is fixed and measured, The following measurement error occurs.

As shown in FIG. 3, when the contact piece O of the probe is pressed against the tooth space between the teeth T1 and T2 from the direction of the arrow,
If the contact piece O is not exactly in the center of the tooth groove, the measured gear W is fixed to the measuring machine and cannot rotate.
Of the contact piece O is stopped, and the position of the contact piece O is measured with a gap S between the tooth T2 and the tooth T2, resulting in a measurement error.

In Japanese Utility Model Laid-Open No. 61-131613, a jig for elastically gripping the shaft portion of a gear with a shaft formed with a gear at its tip with a V block is provided, and the jig is moved two-dimensionally vertically and horizontally. There is described a jig for measuring runout of a tooth groove in which this jig can be freely moved back and forth with respect to a probe attached to a table that is enabled. When measuring the runout of the tooth groove using this measuring jig, the feed force of the tracing stylus is set to be larger than the elastic gripping force of the V block of the gear to be measured. When one of the teeth of the gear to be measured hits, the gear to be measured is rotated against the friction holding force, and the balls hit the tooth flanks on both sides.

[0005]

In the runout measurement of the tooth groove using the measuring jig described in the above-mentioned publication, the gear to be measured is rotated and the balls of the probe contact the teeth on both sides. There is no measurement error due to single-sided contact such as when fixing the gear to be measured. However, by moving the jig supporting the gear to be measured back and forth with respect to the gauge head, the relative position between the ball of the gauge head and the gear to be measured is adjusted. It does not have a mechanism to keep the constant.

When the relative pressing force between the ball and the gear to be measured fluctuates, the accuracy and rigidity of the measuring machine, the gear to be measured and the jig for supporting the gear, and the elastic deformation of the jig cause a deformation of about 20 μm.
The position of the ball fluctuates in the range of m. For example, in JIS (B1704) for accuracy of bevel gears, the pitch circle diameter is 50
For gears of mm or less, the allowable value of runout of the tooth groove is 0 in class 1
4μm, 1st grade 21μm, 2nd grade 31μm, 3rd grade 48
It is specified as μm, and the measurement error due to the fluctuation of the pressing force is a non-negligible amount in terms of the measurement accuracy of the tooth groove runout.

The present invention, when measuring the contact of the tooth space,
It is an object of the present invention to provide a tooth groove runout measuring device having a simpler configuration, which can prevent the contact of the measuring element from being unbalanced, enable a highly accurate measurement by keeping the relative pressing force of the ball and the measured gear constant. is there.

[0008]

According to the present invention, there is provided a work supporting jig rotatably mounted on a base, and a measuring probe provided so as to be swingable in a direction including a central axis of the work supporting jig. A measuring unit consisting of a member for pressing the measurement probe against the work, a member for detecting the pressing force of the pressing member, and a member for detecting the displacement of the measurement probe is installed in the vertical direction and along the swinging direction of the measurement probe. It is also possible to install a member for detecting a height of the measurement unit from the base, which is a tooth groove runout measuring device installed so as to be movable in two-dimensional directions.

[0009]

Operation When the measuring unit whose height is adjusted is moved laterally so that the measuring probe enters the tooth groove of the work and hits one side of the tooth, the work is rotated to hit both sides of the tooth. In this state, the measuring unit is further fed, and when the pressing force of the measuring probe reaches a constant value, the displacement amount of the measuring probe is read.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG.
The work mounting jig 2 is rotatably provided on the base 1, and the work W is attached to the work mounting jig 3 with the work supporting base 3 interposed therebetween. A measurement unit 4 including a measurement probe 5 and the like indicated by a chain line is installed above it. Although not shown, the measurement unit 4 has, for example, the same as a well-known two-dimensional movement table,
It is mounted on the base 1 so that it can be moved up and down and sideways using the vertical and horizontal feed screws.

In the measuring unit 4, a measuring probe 5 is swingably attached to a probe support 6 and a spring 7 for urging the measuring probe 5 counterclockwise is installed. A ball 5a that comes into contact with the tooth groove of the workpiece W is provided at one end of the measurement probe 5, and a ball 5b is provided on the opposite side, and a pressing force detection dial gauge 8 and a linear scale 9 are installed opposite to each other. An indicator 10 is connected to the linear scale 9. The swinging direction of the measuring probe 5 is made to coincide with the surface including the central axis of the rotary jig 2 for mounting the work. That is, in FIG. 1, the measuring probe 5 is provided so that the moving direction of the center of the ball 5a and the axis of the rotating jig 2 are on the plane of the drawing. The measurement height detecting dial gauge 11 is installed on the base 1, and its measuring needle is brought into contact with the lower surface of the probe support 6.

Next, the measurement of the contact of the tooth space with the measuring machine shown in FIG. 1 will be described. First, the work W is placed on the rotary jig 2.
Attached, and the measurement unit 4 is moved to move the measurement probe 5
The ball 5a is positioned substantially in the tooth groove of the work W. Next, the height of the probe support 6 is read by the measurement height detection dial gauge 11, and the measurement unit 4 is moved up and down so that the ball 5a of the measurement probe 5 is at the measurement position shown in FIG. 2A. Adjust. Next, the measuring unit 4 is moved in the lateral direction so that the ball 5a of the measuring probe 5 moves to the work W.
When the tooth W enters the tooth groove and hits one side of the tooth T1 as shown in FIG. 3, the work W is rotated as shown in FIG. 2B to hit both sides of the teeth T1 and T2. When the measuring unit 4 is further moved to the right in the figure in this state, the measuring probe 5 is rotated clockwise by the reaction force of the work W and compresses the spring 7. The displacement amount of the spring 7 is read by the pressurizing force detection dial gauge 8, and when the read value of the pressurizing force detection dial gauge 8 becomes a constant value, the value of the linear scale 9 is read. This value is displayed on the indicator 10.

After the measurement of the tooth groove at one location is completed, the measuring unit 4 is moved in the left lateral direction in FIG.
Rotate by the amount of teeth and measure the next tooth space by the above procedure.
The above measurement is sequentially performed for all tooth spaces, and the data of the total number of tooth spaces of the indicator 10 is collected and analyzed to obtain the grade of tooth groove runout. When measuring workpieces with different dimensions,
By exchanging the work support base 3, the height can be adjusted over a wide range.

In the above-described embodiment, the pressure is applied to the measurement probe 5 by the spring 7 and the pressure is detected by the amount of displacement of the spring. However, the pressure may be applied to the measurement probe by air pressure or hydraulic pressure. However, in this case, the pressure is directly detected. Further, since the measuring unit is only moved in the two-dimensional direction, an inexpensive feed adjusting device such as a two-dimensional feed table can be used.

[0015]

According to the present invention, when the contact of the tooth space is measured, it is possible to prevent one-side contact of the contact point and to make the relative pressing force between the ball and the gear to be measured constant and to perform highly accurate measurement. A tooth groove deflection measuring device having a simple structure can be provided at low cost.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention and is a front view with a part in section.

FIG. 2 is an explanatory diagram of a measurement state.

FIG. 3 is an explanatory view of a conventional measurement state.

[Explanation of symbols]

1 base 2 rotating jig 3 work support
4 Measuring unit 5 Measuring probe 6 Probe support 7 Spring 8 Dial gauge for pressure detection 9 Linear scale 10 Indicator 11 Dial gauge for measurement height detection

[Procedure amendment]

[Submission date] November 24, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 2

[Correction method] Change

[Correction content]

[Fig. 2]

Claims (2)

[Claims] 1. A measurement probe having a work support jig rotatably installed on a base and swingably provided in a direction including a central axis of the work support jig, and a member for pressing the measurement probe onto the work. And a member for detecting the pressing force of the pressure member and a member for detecting the displacement of the measuring probe can be moved in the up-down direction and in the two-dimensional lateral direction along the swing direction of the measuring probe. A tooth groove runout measuring device characterized by being installed in. 2. The tooth groove runout measuring device according to claim 1, further comprising a member for detecting a height of the measuring unit from the base.