JP2017155816A - Manufacturing method of torque limiter unit and upper column shaft - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a torque limiter capable of stably achieving operation torque.SOLUTION: A manufacturing method of a torque limiter in which a tolerance ring as a torque limiter, is disposed between an outer peripheral face of a first rotary member and an inner peripheral face of a second rotary member, includes a fitting process for rotating and sliding the first rotary member in one direction at a fixed rotational angular speed in a state of restricting rotation of the second rotary member. In the fitting process, load torque T of the first rotary member is detected. Conditions to certify an acceptable product in the fitting process, include that change of a detection value Td is saturated after the detection value Td of the load torque T becomes a prescribed value (upper limit value TRmax) within a tolerance rance or less.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a method for manufacturing a torque limiter unit and an upper column shaft unit.

In the ball joint manufacturing method, while rotating the ball stud around the stud shaft, the stud shaft is swung about the center of the ball head of the ball stud, and the resin sheet and the ball head receiving the ball head Has been proposed (see, for example, Patent Document 1).
In addition, in a preload setting method for a tapered roller bearing, a technique has been proposed in which a familiar operation is performed for a short time while being lubricated with a rust preventive oil having a predetermined kinematic viscosity (see, for example, Patent Document 2).

JP 2010-96335 A JP 2002-139055 A

  By the way, in the steering apparatus, an upper column shaft unit in which a tolerance ring is interposed between the upper column shaft and the key lock collar is provided. When a torque exceeding the specified torque is transmitted between the key lock collar and the upper column shaft due to theft, etc., the tolerance ring functions as a torque limiter to perform relative rotation between the upper column shaft and the key lock collar. Allow. Thereby, damage to the upper column shaft is suppressed.

The prescribed torque is determined by the friction between the upper column shaft and the tolerance ring. There is a demand for the specified torque of the torque limiter to be stable.
The inventor of this application assumes that a load torque is applied to the upper column shaft to stabilize the specified torque of the torque limiter, and the conforming process is performed.
However, even if the load torque is within the tolerance range of the specified torque, the change in the load torque may not be saturated. In that case, the operating torque of the torque limiter during actual use may deviate from the tolerance range of the specified torque. This kind of problem exists not only in the upper column shaft unit in the steering apparatus but also in other torque limiter units using a tolerance ring.

  Accordingly, an object of the present invention is to provide a method for manufacturing a torque limiter unit and an upper column shaft unit that can obtain a stable operating torque.

  According to the first aspect of the present invention, a tolerance ring (30) as a torque limiter is interposed between the outer peripheral surface (10a) of the first rotating member (10) and the inner peripheral surface (20a) of the second rotating member (20). A torque limiter unit manufacturing method including a conforming step of rotating and sliding the first rotating member in one direction at a constant rotational angular speed in a state in which the rotation of the second rotating member is restricted. The condition that the load torque (T) of the first rotating member is detected and is recognized as a non-defective product in the conforming process is that the detected value (Td) of the load torque is within the tolerance range (A) of the specified torque (TR). There is provided a method for manufacturing a torque limiter unit (U) including saturation of a change in the detected value after a predetermined value (TRmax) or less.

In the familiarization step, the load torque of the first rotating member is detected, and the load torque is detected. Alphanumeric characters in parentheses indicate corresponding components in the embodiments described later. Of course, It is not meant that the invention be limited to those embodiments. The same applies hereinafter.
As in claim 2, the saturation of the change in the detection value is that the fluctuation amount (ΔTd) of the detection value in the predetermined rotation angle width of the one rotating member is equal to or less than the predetermined amount (e). Good.

According to a third aspect of the present invention, before the conforming step, the first rotating member is rotated forward and backward in a state in which the rotation of the second rotating member is restricted, and the gap between the tolerance ring and the first rotating member is determined. A grease extending step of extending the grease (G) intervening in the substrate may be included.
According to a fourth aspect of the present invention, the first rotating member is an upper column shaft (10), and the second rotating member is a key lock collar (20). A method for manufacturing an upper column shaft unit (U) as a torque limiter unit is provided.

In the first aspect of the present invention, the condition that is recognized as a non-defective product in the familiarization step includes that the change in the detected value is saturated after the detected value of the load torque falls below a predetermined value within a tolerance range. For this reason, the operating torque of the tolerance ring when functioning as a torque limiter during actual use is stabilized.
According to the second aspect of the present invention, it is determined that the change in the detected value is saturated when the amount of change in the detected value of the load torque in the predetermined rotation angle width of the first rotating member is equal to or less than the predetermined amount.

In the invention of claim 3, the grease is spread between the tolerance ring and the first rotating member in the grease extending step before the conforming step. Therefore, stable torque management is possible in the familiarization process.
In the invention of claim 4, during actual use, the operating torque when the key lock collar rotates with respect to the upper column shaft is stabilized.

It is a flowchart of the manufacturing process in the manufacturing method of the upper column shaft unit as a torque limiter unit of one Embodiment of this invention. It is a partially broken side view of the manufactured upper column shaft unit. (A) is a front view of a tolerance ring, (b) is a side view of a tolerance ring. (A)-(d) is process drawing. It is a flowchart of a familiar process. It is a graph which shows the relationship between the rotation angle of an upper column shaft, and load torque in a grease extension process and a conforming process.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.
FIG. 1 is a process diagram showing a flow of a manufacturing method of an upper column shaft unit as a torque limiter unit according to an embodiment of the present invention. FIG. 2 is a schematic sectional view of the upper column shaft unit.
As shown in FIG. 2, the upper column shaft unit U includes an upper column shaft 10 as a first rotating member, a key lock collar 20 as a second rotating member, an outer peripheral surface 10a of the upper column shaft 10, and a key lock collar. And a tolerance ring 30 interposed between the inner peripheral surface 20a of the two.

The key lock collar 20 is formed with a key lock hole 21 into which a lock key of a steering lock device (not shown) is inserted.
FIG. 3A is a front view of the tolerance ring, and FIG. 3B is a side view of the tolerance ring. As shown in FIGS. 3A and 3B, the tolerance ring 30 includes a ring-shaped main body 31 formed of a metal plate continuous in a C shape around the central axis C <b> 1, and a circumferential direction of the main body 31. A plurality of convex portions 32 that are juxtaposed at intervals and project outward in the radial direction of the main body 31 are provided.

Referring to FIG. 2, the tolerance ring 30 regulates relative rotation between the upper column shaft 10 and the key lock collar 20 based on the frictional resistance between the inner peripheral surface 30 a and the outer peripheral surface 10 a of the upper column shaft 10. .
On the other hand, the tolerance ring 30 allows relative rotation between the upper column shaft 10 and the key lock collar 20 when the inner peripheral surface 30a becomes a sliding surface when there is a torque input exceeding the specified torque TR. That is, the tolerance ring 30 functions as a torque limiter.

As shown in FIG. 1, the manufacturing method includes a grease application step (step S1), a tolerance ring external fitting step (step S2), a key lock collar external fitting step (step S3), and a grease extending step (step S4). ) And the familiar process (step S5).
First, in the grease application process in step S1, grease G is applied to the outer peripheral surface 10a of the upper column shaft 10 as shown in FIG.

Next, in the tolerance ring external fitting step in step S2, the tolerance ring 30 is externally fitted to the outer peripheral surface 10a of the upper column shaft 10 as shown in FIG.
Next, in the key lock collar external fitting step of step S3, as shown in FIG. 4C, the key lock collar 20 is externally fitted to the outer peripheral surface 30b of the tolerance ring 30 that is externally fitted to the upper column shaft 10. . Thereby, the manufacturing intermediate body U1 of the upper column shaft unit U is formed.

Next, the grease extending process in step S4 and the conforming process in step S5 are performed in a state where the production intermediate U1 is mounted on the test apparatus 50, as shown in FIG.
The test apparatus 50 includes a frame 51, a pair of bearing portions 52, a rotation restricting portion 53, a drive source 54, a transmission mechanism 55, and a controller 56.
The pair of bearing portions 52 are supported by the frame 51 and support the upper column shaft 10 to be rotatable. The rotation restricting portion 53 is supported by the frame 51, holds the key lock collar 20 from the outer peripheral side, and restricts the rotation of the key lock collar 20.

The drive source 54 is an electric motor supported by the frame 51. The transmission mechanism 55 includes a speed reduction mechanism 55 a that decelerates the power rotation of the drive source 54 and a transmission portion 55 b that transmits the output of the speed reduction mechanism 55 a to the one end 11 of the upper column shaft 10.
A torque sensor 57 that detects a load torque T transmitted to the upper column shaft 10 and an encoder 58 that detects the rotation angle of the upper column shaft 10 are disposed in the transmission portion 55b. Instead of the encoder 58, a resolver arranged in an electric motor as the drive source 54 may be used.

The controller 56 controls the drive source 54 to perform the grease spreading process and the blending process. The load torque T detected by the torque sensor 57 and the rotational speed detected by the encoder 58 are input to the controller 56.
FIG. 6 is a graph showing the relationship between the rotation angle θ of the upper column shaft 10 and the detected value Td of the load torque in the grease extending step and the conforming step. In FIG. 6, the first rotation direction R1 (counterclockwise) is represented by a negative direction, and the second rotation direction R2 (clockwise direction) is represented by a positive direction.

In the grease extending step of step S4, the rotation of the drive source 54 is transmitted through the transmission mechanism 55, and the upper column shaft 10 is rotationally driven.
Specifically, as shown in FIG. 6, after the upper column shaft 10 is rotated 180 ° from the neutral position (rotation angle θ = 0) to the first rotation direction R1 (for example, counterclockwise), the first It is rotated 180 ° in a second rotation direction R2 (for example, clockwise) that is opposite to the rotation direction R1. As a result, the upper column shaft 10 is returned to the neutral position, and the grease extending step is completed.

By rotating the upper column shaft 10 forward and backward in the grease extending step, the grease G can be spread over the entire circumference of the outer peripheral surface 10 a of the upper column shaft 10.
Next, the conforming process of step S5 is performed continuously with the grease extending process in a state where the production intermediate U1 is mounted on the test apparatus 50. The familiar process is performed based on the familiar process flow shown in FIG.

In the familiarizing process, first, the upper column shaft 10 is rotated in the second rotational direction R2 at a constant rotational angular velocity V (for example, V = 90 ° / second) (step Q1). The torque sensor 57 detects the load torque T transmitted to the upper column shaft 10 as the detection value Td (step Q2).
Next, at step Q3, it is determined whether or not the detected value Td by the torque sensor 57 is equal to or less than the upper limit value TRmax of the tolerance range A of the specified torque TR (lower limit value TRmin ≦ TR ≦ upper limit value TRmax).

In step Q3, if the detected value Td exceeds the upper limit value TRmax (NO in step Q3), the process returns to step Q2, and the processing of steps Q2 and Q3 is repeated to monitor the detected value Td.
On the other hand, if the detected value Td is equal to or lower than the upper limit value TRmax in step Q3 (YES in step Q3), the process proceeds to step Q4. In step Q4, as shown in FIG. 6, the fluctuation amount ΔTd of the detection value Td in a predetermined rotation angle width Δθ (for example, a section where Δθ = 30 °) is sampled.

Next, in step Q5, whether or not the change in the detection value Td is saturated, specifically, whether or not the fluctuation amount ΔTd of the detection value Td in the predetermined rotation angle width Δθ is equal to or less than the predetermined amount e (ΔTd ≦ e). It is determined whether or not.
In step Q5, if the fluctuation amount ΔTd exceeds the predetermined amount e (ΔTd>e; if NO in step Q5), it is determined that the change in the detected value Td is not saturated, and step Q4 is performed via step Q6. Returning to step S4, the processes in steps Q4 and Q5 are repeated to monitor the variation ΔTd.

In step Q6, it is monitored whether or not the total number of rotations in the conforming process is 10 or less (θ ≦ 3600 °). That is, if the total number of revolutions is 10 or less (YES in step Q6), the process returns to step Q4. If the total number of revolutions exceeds 10 (NO in step Q6), upper column shaft unit U is recognized as a defective product (step Q9).
On the other hand, when the fluctuation amount ΔTd becomes equal to or smaller than the predetermined amount e in step Q5 (ΔTd ≦ e. If YES in step Q5), it is determined that the change in the detection value Td is saturated, and the process proceeds to step Q7. When the detected value Td is equal to or higher than the lower limit value TRmin (YES in step Q7), the upper column shaft unit U is recognized as a non-defective product (step Q8).

If the detected value Td is below the lower limit value TRmin in step Q7 (NO in step Q7), the upper column shaft unit U is recognized as a defective product (step Q9).
In the present embodiment, in the conforming process, even after the detected value Td of the load torque T falls within the tolerance range A of the specified torque TR (lower limit value TRmin ≦ TR ≦ upper limit value TRmax), the rotation sliding is continued and detected. The change of the value Td is sampled. The condition for qualifying as a non-defective product in the familiarization process is that the change in the detected value Td is saturated after the detected value Td of the load torque falls below a predetermined value (upper limit value TRmax) within the tolerance range A of the specified torque TR. including. For this reason, during actual use, the operating torque of the tolerance ring 30 when functioning as a torque limiter is stabilized. That is, the operating torque when the key lock collar 20 rotates with respect to the upper column shaft 10 is stabilized. Thereby, the defect rate can be reduced.

Further, it is not necessary to perform complicated operations such as grouping the components of the upper column shaft unit U for each tolerance variation, and selecting and assembling those having good compatibility. Further, it becomes possible to set the tolerance of the component parts loosely, and in this case, the manufacturing cost can be reduced.
Further, when the fluctuation amount ΔTd of the detection value Td of the load torque T in the predetermined rotation angle width Δθ of the upper column shaft 10 is equal to or less than the predetermined amount e (ΔTd ≦ e), the change in the detection value Td is saturated. To be judged.

Further, the grease G is spread between the tolerance ring 30 and the upper column shaft 10 in the grease extending step before the conforming step. For this reason, in the conforming process, it is difficult for the grease to run out, and stable torque management becomes possible.
The present invention is not limited to the above-described embodiment. For example, the first rotation direction R1 may be clockwise and the second rotation direction R2 may be counterclockwise.

Further, in step Q3 in FIG. 5, instead of the upper limit value TRmax on the right side, a median value [(TRmax + TRmin) / 2] within the tolerance range A of the specified torque TR may be used. That is, in step Q3, it may be determined whether or not the detected value Td is equal to or less than the median value [(TRmax + TRmin) / 2] within the tolerance range A of the specified torque TR.
Further, the present invention can be applied to other torque limiter units in which a tolerance ring is interposed between the first rotating member and the second rotating member. In addition, the present invention can be variously modified within the scope of the claims.

  DESCRIPTION OF SYMBOLS 10 ... Upper column shaft (1st rotation member), 10a ... Outer peripheral surface, 20 ... Key lock collar (2nd rotation member), 20a ... Inner peripheral surface, 21 ... Key lock hole, 30 ... Tolerance ring (torque limiter), 30a ... Inner peripheral surface, 30b ... Outer peripheral surface, A ... Tolerance range, G ... Grease, R1 ... First rotation direction, R2 ... Second rotation direction, T ... Load torque, Td ... Detected value, ΔTd ... Variation amount, e ... Predetermined amount, TR ... Specified torque, TRmax ... Upper limit value, TRmin ... Lower limit value, U ... Upper column shaft unit (torque limiter unit)

Claims (4)

A manufacturing method of a torque limiter unit in which a tolerance ring as a torque limiter is interposed between an outer peripheral surface of a first rotating member and an inner peripheral surface of a second rotating member,
Including a conforming step of rotating and sliding the first rotating member in one direction at a constant rotational angular speed with the rotation of the second rotating member restricted;
In the conforming step, a load torque of the first rotating member is detected,
A method for manufacturing a torque limiter unit, wherein the condition for qualifying as a non-defective product in the conforming step includes saturation of a change in the detected value after the detected value of the load torque becomes equal to or less than a predetermined value within a tolerance range of a specified torque. .   2. The method of manufacturing a torque limiter unit according to claim 1, wherein the saturation of the change in the detection value is that a fluctuation amount of the detection value in a predetermined rotation angle width of the one rotation member is equal to or less than a predetermined amount.   3. The method according to claim 1, wherein, before the conforming step, the first rotating member is rotated forward and backward in a state where the rotation of the second rotating member is restricted, and the gap between the tolerance ring and the first rotating member. A method of manufacturing a torque limiter unit including a grease extending step of extending grease intervening in the motor.   The manufacturing method of the upper column shaft unit as a torque limiter unit as described in any one of Claims 1-3 with which the said 1st rotation member is an upper column shaft, and the said 2nd rotation member is a key lock collar.

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