JPS6036005B2 - Worm gear tooth trace measuring device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a tooth trace measuring device for a worm gear.

Currently, there are no accuracy standards for worm gears, and the causes of problems such as noise are not fully understood.

However, in order to standardize mass-produced worm gears and ensure compatibility, it is important to measure the accuracy of worm gears. Commercially available gear testing machines can measure the tooth profile, force angle, circular pitch, etc. of worm gears, but cannot measure tooth traces.

This is because, as shown in Fig. 1, each tooth 2 of the worm gear 1 is usually made with a hollow part that hugs a part of the periphery of the worm 3 with which it engages, and the side surface of each tooth 2, that is, the tooth This is because the streaks draw the same spiral as worm 3.
The present invention has been proposed in view of the current situation, and it is an object of the present invention to provide a tooth trace measuring device that can accurately measure the tooth trace of a worm gear with a relatively simple mechanism. The measurement principle of the present invention is to cause the tip of the probe that comes into contact with the side surface of the tooth profile of the worm gear to be measured to perform an arcuate motion with a radius equal to the radius of the pitch circle of the worm that meshes with the worm gear.
On the other hand, the present invention is characterized in that rotational displacement is applied to the worm gear at a constant ratio in conjunction with the arcuate movement of the probe.

That is, between the displacement L due to the circular arc movement of the tip of the measuring tip and the rotational displacement T of the worm gear,
(1) However, L is the worm lead D is the diameter of the worm pitch circle 8 is the worm lead angle draws a correct tooth trace trajectory with no errors.

Therefore, the error in the tooth trace can be measured by examining the unevenness of the tooth surface detected by the probe. This is the measurement principle of the present invention. Embodiments of the present invention will be described below with reference to the drawings.

10 is a base, and 11 is a gear support, which is reciprocated along the upper surface of the base 10 by rotating a screw shaft 13 screwed into a female screw body 12 fixed to the bottom with a manual handle 14.

Reference numeral 15 denotes a first reference disk, which has a diameter equal to the pitch circle of the worm gear 16 to be measured, and has a spindle 17 erected on the gear support 11 so as to be rotatable around its axis.
It is removably attached to.

The worm gear 16 is disposed coaxially with the first reference disk 15 with both ends of the test arbor 18 supported by a spindle 17 and a spindle 17' provided at the upper end of the gear support base 11, and the rotary ring 19 is via the first reference disk 15
It is designed to rotate integrally with the A plane perpendicular to the axis of the worm gear 16 supported in this manner and passing through the center of the teeth 16a is defined as a measurement reference plane m. A second base adjacent to the end of the base 10 and extending perpendicularly to the base 10' (see FIG. 3).

Reference numeral 21 denotes a movable platform mounted on the top surface of the base 20, which can be reciprocated along the longitudinal direction of the base 20 by rotating a threaded rod 23 screwed into a female threaded body 22 rotatable at the bottom with a manual handle 24. It has become.

Reference numeral 25 denotes a detector holding stand placed on the movable stand 21, and by rotating a threaded rod 27 screwed into a female threaded body 26 fixed to the bottom thereof with a handle 28, it is moved in a direction perpendicular to the moving direction of the movable stand 21. It is possible to move back and forth.

Reference numeral 29 is an elevating block that is attached to the detector holding base 25 so as to be movable up and down by means of a screw face 30 and a handle 31.A rotating shaft 32 extending parallel to the moving direction of the movable base 21 is attached to the protruding front end of the lift block. It is freely supported.

A second reference disk 33 has a diameter equal to the pitch circle of a worm (not shown) that meshes with the worm gear 16 to be measured, and is fixed to one end of the rotating shaft 32.

Therefore, the sum of the radii of the first and second reference discs 15 and 33 is equal to the distance between the axes of the worm gear 16 to be measured and the worm that meshes with it, and the second reference disc 33
When arranged in the same D shape as the worm, it comes into contact with the pitch circle of the worm gear 16 on the measurement reference plane m. 35 is a detector, 35a is its probe, and the detector 35 is a mounting plate 34 fixed to the end of the rotating shaft 32.
The probe 35a is attached to the rotary shaft 32 so that the probe 35a moves in an arc around the axis at a radius approximately equal to the pitch circle of the worm.

Prior to measurement, the handles 24, 28, and 31 are rotated to move the detector 35 back and forth, left and right, and up and down, and the axis of the rotation shaft 32, which is the center of rotation of the probe 35a, is placed on the measurement reference plane m. The tip of the probe 35a is brought into contact with the side surface of the tooth 16a of the worm gear 16. Reference numeral 36 denotes a first sliding plate disposed along the side surface of the base 20, which rolls into contact with the circumferential surface of the first reference disk 15 during measurement.

Reference numeral 37 denotes a second driving plate that rolls into contact with the second reference disc 32, and is connected to the lifting block 39 via a connecting plate 38, as shown in FIGS. 3 and 4.

The elevating block 39 is mounted so as to be movable up and down by means of a holding base 41 fixed to the base 201 and a handle 42. 43 is a crosshead guide plate provided with a groove 44 extending in the diametrical direction, as best shown in FIG. Therefore, the inclination angle 0 of the groove 44 with respect to the vertical movement direction can be adjusted as desired.

Reference numeral 46 designates an actuating member fixed to the first sliding plate 36, and its end portion is pivotally connected to a slider 45 that engages with the groove 44. When the handle 42 is rotated with the lead angle 3 of the worm gear 15 for measuring the inclination angle a of the groove 44 of the crosshead guide plate 43, the crosshead guide plate 43, the connecting plate 38, and the second sliding plate are rotated. 37 rise together, and the first sliding plate 36 moves to the fourth via the slider 45 and the operating punch 46.
It is moved to the left in the figure.

The ratio of the displacement t of the first sliding plate 36 to the displacement 02 of the second sliding plate 37 and the inclination angle 8 of the groove 44 have the same relationship of poison = geodetic n3 as in the above equation (1). It is clear from FIG. 4 that this holds true.

and first and second reference discs 15 that interlock with and roll into contact with the first and second sliding plates 36 and 37,
33 are rotated by an arc equal to the displacement length t and , respectively, the rotational displacement of the first reference disk 15 is the rotational displacement of the worm gear 16 to be measured, and the rotational displacement of the second reference disk 33 is Since is the rotational displacement of the probe 35a,
As a result, a rotational displacement that satisfies the above equation {1} is given between the measuring tip 35a and the worm gear 16, and the measuring tip 35a
The tip of the worm gear 16 and the worm gear 16 draw a correct tooth trace trajectory without any errors. Therefore, the error in the tooth trace of the worm gear 16 can be measured by transmitting and recording the unevenness of the tooth surface 16a detected by the measuring element 35a to a recording device (not shown).

As explained above, according to the apparatus of the present invention, it is possible to easily measure the accuracy of the tooth trace of a worm gear.

Furthermore, the mechanism of the device is simple and it is extremely easy to manufacture and handle.

[Brief explanation of the drawing]

Fig. 1 is a diagram for explaining the relationship between a worm gear and a worm that meshes with the worm gear, Fig. 2 is a partially longitudinal front view of the tooth trace measuring device of the present invention, Fig. 3 is a plan view of the same, and Fig. 4 is FIG. 4 is a view taken along line 4-4 in FIG. 3; 15...First reference disk, 16...Worm gear, 33...Second reference disk, 35...
...Detector, 35a...Measuring head, 36...
...First oak board, 37...Second sliding board, 43
...Crosshead information board. Figure 1 Figure 4 Figure 2 Figure 3

Claims (1)

[Claims] 1. A first reference disk having a diameter equal to the diameter of the pitch circle of the worm gear to be measured and rotationally displaced coaxially with the worm gear, and a worm gear meshing with the worm gear. a second reference disk rotatably arranged around the axis and having a diameter equal to the diameter of the pitch circle of the worm; and a second reference disk connected to the rotation axis of the second reference disk and centered around the rotation line core. A measuring element that makes an arcuate motion as the tip of the worm gear contacts the tooth profile side surface of the worm gear, and the ratio of the rotational displacement of the first reference disk to the displacement accompanying the arcuate movement of the second reference disk is determined by the worm. and an interlocking mechanism for rotationally displacing the first and second reference disks so as to maintain a relationship that corresponds to the tangent of the lead angle of the worm gear. 2. The tooth trace measuring device for a worm gear according to claim 1, wherein the ratio of rotational displacement of the first and second reference discs is adjustable.