JPH076791B2 - Rack tooth twist angle measuring device for rack shaft - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a rack shaft constituting a rack and pinion type steering device for an automobile, in which rack teeth formed on the rack shaft are in the shape of a helical pin. The present invention relates to a rack tooth twist angle measuring device for a rack shaft, which can easily and quickly determine whether or not the twist angle of the helical teeth is accurately formed and determine whether the rack shaft is a good product or a defective product.

[Conventional technology and its problems]

On the rack shaft that constitutes the rack and pinion type steering device of the automobile, the rack teeth formed on this are in the shape of a helical pin, and it is measured whether or not the helical angle of the helical pin is accurately formed. The inspection work for discriminating the non-defective product from the defective product has conventionally been performed manually by a worker.

However, the number of rack shafts manufactured at the factory is large,
In addition, since various rack shafts with different twist angles θ of the helical teeth may be manufactured, the conventional manual inspection may be time-consuming and may cause an inspection error, and eventually a defective product will be shipped. It causes a lot of damage.

Under such circumstances, there is a demand for an apparatus that can satisfy inspection efficiency, time reduction, and accuracy at one time.

[Means for Solving the Problems]

Therefore, as a result of earnest and repeated studies, the inventor of the present invention has found that, as a result of the invention, a probe provided with a measuring rod is pivotally supported on an elevating substrate so as to be rotatable on a horizontal plane, and the probe is The rack motor is provided with a belt motor so as to rotate synchronously with the angle detection sensor provided on the lifting board, and the lifting board can be vertically lifted to form a rack shaft rack tooth twist angle measuring device, or in the above configuration, A rack tooth twist angle measuring device for a rack shaft that allows the lifting board to be vertically lifted by a fluid pressure cylinder and can be lowered by its own weight when it is lowered, or a probe provided with a measuring rod is used as the lifting board. A rotatably supported shaft is supported on a horizontal plane, and its stylus is belted so as to rotate synchronously with the pulse motor and angle detection sensor provided on the lifting board, and both mounting positions of the opposing rack shaft supports are virtual. A rack tooth twist angle measuring device for a rack shaft in which a mounting plate is supported by opposing compression coil springs so as to be finely movable in the axial direction, and the elevating substrate can be vertically moved on the mounting plate, or In the above structure, the mounting plate is a rack tooth twist angle measuring device for a rack shaft provided on the bed so as to be slidable in a direction intersecting with the virtual center line. The corners can be measured automatically and accurately, a non-defective product and a defective product can be discriminated, and the inspection can be performed quickly, which solves the above problems.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 15.

Reference numeral 1 denotes an elevating board, on which a tracing stylus 3, a pulse motor 4, and an angle detection sensor 5 are respectively provided. The elevating board 1 is configured to be lifted directly above the movable table A by a fluid pressure cylinder 2 which is vertically expanded and contracted by hydraulic pressure or pneumatic pressure.

In the tracing stylus 3 provided on the elevating board 1, the measuring rod 3b is horizontally fixed to the lower surface of the substantially disk-shaped measuring base 3a, and the rotary shaft 3c is fixed to the center of the upper surface of the measuring base 3a. Measuring base 3a
Is pivotally supported on the elevating / lowering board 1 so as to be located below the elevating / lowering board 1, and its measurement base 3a is rotatable on a horizontal plane. As shown here, the probe 3 is an auxiliary substrate.
It may be axis-mounted to 1a. The auxiliary substrate 1a is formed so as to protrude from the elevating substrate 1, and the measuring element 3 is provided at the protruding portion.
Is provided. The auxiliary substrate 1a is formed thicker than the elevating substrate 1 and has a bearing internally mounted therein, and the rotary shaft 3c of the probe 3 is fitted and supported in the bearing. Measuring base 3a
Is configured to be rotatable even with an extremely small external force. The measuring rod 3b has a circular cross section, and is fitted between the adjacent rack teeth Rg, Rg of the tooth portion of the rack axis R described later. Specifically, both ends of the cross section of the measuring rod 3b have a diameter necessary for contacting the opposing rack teeth Rg, Rg. The rotating shaft 3c of the tracing stylus 3 projects from above the elevating board 1, and a belt wheel 6a is fixed to the projecting portion.

The pulse motor 4 is provided below the elevating board 1, and the output shaft 4a thereof projects from the upper surface of the elevating board 1. A belt wheel 6b is fixed to the output shaft 4a.

The main body of the angle detection sensor 5 is provided below the elevating board 1, and the input shaft 5 a thereof projects onto the elevating board 1. A belt wheel 6c is also fixed to the input shaft 5a. The tracing stylus 3, the pulse motor 4, and the angle detection sensor 5 are arranged at positions on the elevating board 1 so as to form a triangular shape in plan view, and three belt wheels 6 are provided on each of them.
A, 6b, 6c belt 7 is wound around. The outer peripheral side surfaces of the respective belt wheels 6a, 6b, 6c are tooth-shaped, and the corresponding belt 7 is also provided with tooth-shaped portions. And
Each belt wheel 6a, 6b, 6c is designed not to slip with respect to the belt 7.

Reference numeral 8 denotes a tensioning wheel, which applies an appropriate tension to the belt 7. The elevating board 1 is provided on the movable base A via three vertical guides 9, 9, 9 as seen in a plane as shown in FIG. The vertical guide 9 is a guide receiver 9a.
A guide bar 9b expands and contracts in the shape of a piston rod, the tip of the guide bar 9b is attached to three places on the lower surface of the elevating board 1, and the lower end of the guide receiver 9a is fixed on the movable table A. Between the movable base A and the position of the lifting board 1 corresponding to the position of the center of gravity of the vertical guides 9, 9, 9 in plan view, the fluid pressure cylinder 2 by hydraulic pressure or pneumatic pressure is used.
And a piston rod of the fluid pressure cylinder 2
The tip of 2a is in contact with a pressing piece 10 provided on the lower surface of the elevating board 1. And the piston rod 2a of the fluid pressure cylinder 2
When the piston rod 2a is housed in the fluid pressure cylinder 2, the tip of the piston rod 2a is separated from the pressing piece 10, and the lifting substrate 1 is lifted vertically. It descends by its own weight through 9,9. In this way, the lifting board 1 is raised by the fluid pressure cylinder 2, and the lifting board 1 is lowered by its own weight. The probe 3 moves up and down as the elevator board 1 moves up and down.

The movable table A moves the elevating board 1 and the tracing stylus 3 provided on the elevating board 1 forward to a position directly above the measured portion (tooth portion) of the rack axis R arranged on the rack shaft supporting section 20 described later, or It is to move backward so as to move away from that position. That is, the bed B is provided with a mounting plate 17 which is slidable in a direction (preferably an orthogonal direction) intersecting with the virtual center line g of both mounting positions of the rack shaft supporting portions 20, 20, which will be described later. Specifically, the movable table A is mainly composed of a movable substrate 11 and a mounting plate 17. The movable substrate 11 has sliding pieces 12, 12 fixed to the lower surfaces of both ends in the width direction (the direction perpendicular to the paper surface of FIG. 1 and the vertical direction in FIG. 15) of the movable board 11 in the front-back direction of the bed B ( Vertical plates 13, 13 are provided at both ends in the left-right direction in FIGS. 1, 13, and 15), and between the vertical plates 13, 13.
Two guide rails 14, 14 are arranged in parallel with each other in a direction orthogonal to an imaginary center line g of both mounting positions of rack shaft supporting portions 20, 20, which will be described later, and the guide rails 14, 14 slide in the guide rails 14, 14. Piece 12,
12 is slidably provided.

In addition, a rising piece is formed on the upper surface of both ends of the movable substrate 11 in the width direction (the direction perpendicular to the paper surface of FIG. 1 and the vertical direction in FIG. 14).
15 and 15 are erected, and the guide rail 1 is provided between the rising pieces 15 and 15.
Reference numerals 6 and 16 are provided in parallel with and horizontally with respect to an imaginary center line g of both mounting positions of the rack shaft supporting portions 20 and 20, which will be described later. A mounting plate 17 is slidably provided in the guide rails 16 and 16 and is movable in the same direction as the virtual center line g. Further, a compression coil spring 18 is provided between each rising piece 15 and the mounting plate 17 so that the pressure can be adjusted by a screw rod 19, and the mounting plate 17 is provided by the presence of both compression coil springs 18, 18. Is always located at the center between the rising pieces 15 and 15 and is capable of fine movement. The compression coil spring 18 is the lifting board 1 provided with the probe 3 and the like.
The pressure is adjusted by the screw rod 19 so that the compression coil spring 18 can be easily expanded and contracted by the force of falling by its own weight.

The rack shaft support portion 20 has two rollers 20a, 20a,
It is provided on the bearing frame 20b so as to be narrower than the shaft diameter of the rack shaft R. The bearing frame 20b is
It is firmly fixed on the bed B. The rack shaft support portions 20 are arranged at two places with an appropriate interval, and the rack shaft R is supported by both rack shaft support portions 20, 20.

The rack shaft fixing portion C includes a fixing fluid pressure cylinder 21 and a fixing piece.
The fixing piece 22 is provided at the tip of the piston rod 21a of the fixing fluid pressure cylinder 21. And
When the piston rod 21a expands and contracts, it rotates 90 ° in the diameter direction of the bearing of the rod, and at the same time, the fixed piece 22 also swivels 90 °. The rack shaft fixing portion C is set so that the tooth surface of the rack shaft R arranged on the rack shaft supporting portion 20 is pressed by the fixing piece 22 so that the tooth surface of the rack shaft R faces accurately upward. To do.

The pulse motor 4 sets the contact point 3 in advance to approximate the twist angle θ when measuring the twist angle θ of the rack teeth. The approximate angle is about ± 1 ° with respect to the twist angle θ. The angle detection sensor 5 performs accurate angle adjustment in advance with a block having a reference angle, and performs angle detection measurement based on the angle.

The measured value of the twist angle θ of the rack tooth Rg, which is larger than the value stored in advance in a calculation display (not shown) connected to the angle detection sensor 5, is transmitted from the probe 3 via the angle detection sensor 5. Send a signal to the calculation display. The twist angle θ of the rack tooth and its allowable limit value (processing control value) are input in advance to the calculation display. For example, twist angle 20 ° ± 10 '
In case of, enter the upper and lower values of 20 ° +10 'and -10' in the degree setting. The calculation display device compares the value (signal) from the angle detection sensor 5 with a preset value to make a pass / fail judgment. Specifically, a slight error angle Δθ of the twist angle θ
Within (for example, about 1/60 ° ≈0.0017 °), it is considered as a passing product. Further, not only the judgment but also the measured value can be numerically confirmed by a direct display meter (angle display meter).

〔The invention's effect〕

First, in the invention of claim 1, the measuring element 3 provided with the measuring rod 3b is pivotally supported on the elevating substrate 1 so as to be rotatable on a horizontal plane, and the measuring element 3 is provided on the elevating substrate 1 by a pulse motor 4 and Wrap the belt 7 so that it rotates synchronously with the angle detection sensor 5,
First, the rack tooth twist angle measuring device for the rack shaft is provided which is capable of vertically moving the elevating board 1.
In addition, the twist angle θ of the rack tooth Rg of the rack shaft R can be measured quickly and accurately, and secondly, the measurement can be automatically performed, and the working efficiency can be improved.

These effects will be described in detail. Since the tracing stylus 3 is rotatably supported on the elevating board 1 on the horizontal plane, the tracing stylus 3
The measuring rod 3b provided at the position also rotates. When the tracing stylus 3 is lowered from just above the measured portion of the rack axis R, the measuring rod 3b
Is rotated so as to be sandwiched between the rack teeth Rg, Rg of the tooth portion of the rack axis R, and the angle detection sensor 5 that rotates synchronously with the probe 3 is displaced by a corresponding angle. If it is larger than the value stored in advance in the operation display connected to the detection sensor 5, it can be determined as a defective product. In this way, simply by bringing the tracing stylus 3 into contact with the tooth surface of the rack axis R, the tracing stylus 3 rotates, and the angle detection sensor 5 detects the rotated displacement amount, and the accurate rack axis R
It is possible to measure the twist angle θ of the rack tooth Rg of
The measurement has the effect that it can be done quickly.

Further, the measurement has a great advantage that it can be automatically performed unlike the conventional method.

Next, in a second aspect of the present invention, in the first aspect of the invention, the rack teeth of the rack shaft are configured such that the elevating substrate 1 can be vertically raised by a fluid pressure cylinder 2 and can be lowered by its own weight when it is lowered. By using the twist angle measuring device,
In particular, when inserting the measuring rod 3b so as to sandwich it between the rack teeth Rg, Rg of the rack shaft R, for example, the solid line in FIG.
As shown in the figure, even if the rack tooth Rg is displaced in the longitudinal direction, it is pressed with a small force called its own weight.
As shown in Fig. 11, the measuring rod 3b is aligned in the longitudinal direction of the rack tooth Rg, its pressing force is constant, and the twist angle θ of the rack tooth Rg can be measured without damaging the rack tooth Rg surface. is there.

Next, in the invention of claim 3, in the invention of claim 1, compression coil springs that oppose each other in the virtual center line g direction of both mounting positions of the rack shaft support portions 20, 20 that oppose each other.
By using the rack tooth twist angle measuring device of the rack shaft that supports the mounting plate 17 so that it can be finely moved by 18, 18, it is possible to measure, for example, when the tracing stylus 3 contacts the tooth surface of the rack shaft R. Rod
Even when 3b comes into contact with the top of the rack tooth Rg, the contact point 3
However, since it is finely moved in the axial direction of the rack tooth R via the fine movement of the mounting plate 17, the measuring rod 3b is always fitted between the rack teeth Rg and Rg (see FIG. 11), and in any case, the rack tooth The twist angle θ of Rg can be measured.

Next, in the invention of claim 4, in the invention of claim 1, a mounting plate 17 slidable in a direction intersecting with the virtual center line g of both mounting positions of the opposing rack shaft support portions 20, 20. Since the bed B is provided so as to move away from the virtual center line g, a large upper space can be secured at the time of setting the rack axis R to the measurement position, which facilitates automatic loading and unloading of the apparatus. In addition, the operating range of the transfer device is not restricted.

Further, by appropriately moving the mounting plate 17 in the direction of the virtual center line g, the rack shaft is used for connecting the rack shaft R to a measuring device at another processing point and for incorporating it as an inspection device such as a transfer machine. It is possible to easily deal with a transfer device that transfers from device to device.

Further, at the time of measurement, there is an advantage that an appropriate position can be selected to facilitate measurement.

The other configurations of the first to third aspects are the same as the invention of the first aspect, and an effect equivalent to this can be exhibited.

[Brief description of drawings]

The drawings show an embodiment of the present invention, in which FIG. 1 is a side view of the present invention, FIG. 2 is a plan view of the present invention, FIG. 3 is a schematic side view of a fixing portion, and FIG. FIG. 7 is a perspective view of the probe head from the bottom side, FIG. 5 is a cross-sectional view of the essential portion of the present invention, FIG. 6 is a state view in which the probe of the present invention is positioned on the rack shaft, and FIG. FIG. 8 is an enlarged plan view showing the measuring rod positioned on the rack shaft, FIG. 9 is a sectional view of FIG. 8, and FIG. 10 is a measuring rod positioned on the rack shaft. Enlarged plan view, FIG. 11 is a sectional view of FIG. 10, FIG. 12 is a schematic plan view of the whole of the present invention, and FIG. 13 is a sectional view of a mounting plate portion of the present invention.
FIG. 14 is a sectional view taken along the line PP of FIG. 13, and FIG. 15 is Q of FIG.
It is a Q-arrow sectional view. 1 ... Lifting board, 2 ... Fluid pressure cylinder, 3 ... Measuring element, 3b ... Measuring rod, 4 ... Pulse motor, 5 ... Angle detection sensor, 7 ... Belt, 17 ... Mounting plate, g ... virtual center line, B ... bed, 18 ... compression coil spring, 20 ... rack shaft support.

Claims (4)

[Claims] 1. A measuring element provided with a measuring rod is pivotally supported on an elevating board so as to be rotatable on a horizontal plane, and the measuring element is belted so as to rotate in synchronization with a pulse motor and an angle detection sensor provided on the elevating board. In addition, the rack tooth twist angle measuring device of the rack shaft is characterized in that the elevating substrate can be vertically moved. 2. A measuring element provided with a measuring rod is pivotally supported on an elevating board so as to be rotatable on a horizontal plane, and the measuring element is belted so as to rotate synchronously with a pulse motor and an angle detection sensor provided on the elevating board. Further, the rack tooth twist angle measuring device of the rack shaft is characterized in that the elevating substrate can be vertically moved by a fluid pressure cylinder and can be lowered by its own weight when being lowered. 3. A measuring element provided with a measuring rod is rotatably supported on an elevating substrate so as to be rotatable on a horizontal plane, and the measuring element is belted so as to rotate in synchronization with a pulse motor and an angle detecting sensor provided on the elevating substrate. Then, the mounting plate is supported by the opposing compression coil springs so that the mounting plate can be finely moved in the virtual center line direction of both mounting positions of the opposing rack shaft support parts, and the elevating substrate can be vertically moved up and down on the mounting plate. A rack tooth twist angle measuring device for a rack shaft. 4. A measuring element provided with a measuring rod is rotatably supported on an elevating substrate so as to be rotatable on a horizontal plane, and the measuring element is belted so as to rotate in synchronization with a pulse motor and an angle detection sensor provided on the elevating substrate. Then, the bed is provided with a mounting plate on which the opposing rack shaft supporting portions can slide in a direction intersecting with the virtual centerlines of both mounting positions, and the lifting board can be vertically moved on the mounting plate. A rack tooth twist angle measuring device for a rack shaft.