JP2825161B2 - Thread bush tightening method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thread bush tightening method.

(Prior Art) Generally, an upper arm shaft is assembled to an A-shaped upper arm that constitutes a suspension of a vehicle such as an automobile. In this mounting area, first, both ends of the upper arm shaft are inserted into mounting holes formed at both ends of the upper arm. Next, two thread bushes are inserted into both mounting holes of the upper arm, and the internal thread portions formed on the inner periphery of each thread bush are respectively inserted into the external thread portions formed at both ends of the upper arm shaft. The external thread formed on the outer periphery of the upper arm is screwed into the female thread formed in each mounting hole of the upper arm by the operation of a tightening jig such as a nut runner, and the two thread bushes are simultaneously tightened. On the other hand, the upper arm shaft is assembled.

Then, in this case, the threading timing of each thread portion of the thread bush to each thread portion of the upper arm and the upper arm shaft is not the same, and generally, the female thread portion of the thread bush is threadedly engaged with the male thread portion of the upper arm shaft. After the start, the male thread of the thread bush starts to screw into the female thread of the upper arm.

(Problems to be Solved by the Invention) However, in the method of simultaneously tightening the two thread bushes as described above, when both thread bush tightening operations proceed at the same time and there is no deviation in the screwing timing of each screw portion on both sides. Although there is no problem, when each female thread of both thread bushes starts screwing with each male thread of the upper arm shaft, when each male thread of both thread bushes is screwed with each female thread of the upper arm, There is a case where the screwing timing of each screw portion on both sides is slightly shifted, and the screwing on one side is performed one step earlier than the other side at a stage where the screwing has not yet reached the effective screw portion area. in this case,
The upper arm is slightly displaced on the other side due to contact resistance when screwed on one side, and the center stopper of the mounting hole of the upper arm and the shaft stopper of the thread bush on the other side are displaced due to this displacement. In some cases, an unacceptable phase shift occurs. As described above, when the upper arm is displaced, the male thread portion of the thread bush is not screwed into the female thread portion of the mounting hole of the upper arm in a regular state, and the subsequent thread bush tightening operation is performed accurately. Can not do.

Therefore, instead of performing both thread bush tightening operations at the same time, it is conceivable to perform the other tightening operation after one tightening operation is completed. As a result, the tightening operation takes twice as long and the cycle time becomes longer.

The present invention has been made in view of such a point, and an object thereof is to provide a first assembling part such as an upper arm having a female screw portion in each of a pair of assembling holes formed at both ends as described above. When assembling a second assembly component such as an upper arm shaft having a pair of male screw portions at both ends, by appropriately setting the tightening timing of the two thread bushes having screw portions to be screwed into the respective screw portions,
An object of the present invention is to perform a thread bush tightening operation accurately and in a short time.

(Means for Solving the Problems) In order to achieve the above object, a solution of the present invention is to provide a first assembling component having a female screw portion in each of a pair of assembling holes formed at both ends, In order to assemble with the second assembling part having a pair of male screw parts, in a state where each male screw part of the second assembling part is inserted into each assembling hole of the first assembling part,
Two thread bushes each having a female thread portion on the inner periphery and a male thread portion on the outer periphery are inserted into both mounting holes of the first assembly component, and the female thread portions of each thread bush are inserted into each of the second assembly components. As a method of screwing the male thread of each thread bush to the female thread of the first assembled part to the male thread and tightening the thread bush,
One thread bush tightening operation for the first and second assembled parts is started. Next, after the tightening torque by the preceding one thread bush tightening operation becomes the tightening torque set value in a state where each of the threaded screw portions has reached the effective screw portion region by the progress of the tightening operation, or After the time required from the start of the preceding one thread bush tightening operation to the time when each of the threaded screw portions reaches the effective thread portion area by the progress of this tightening operation has elapsed, the succeeding other thread bush tightening operation is performed. Get started.

(Operation) With the above configuration, in the method of the present invention, first, the first assembled component is inserted in a state where the pair of male screw portions of the second assembled component are inserted into the pair of assembly holes of the first assembled component, respectively. A threaded bush is inserted into one of the mounting holes, and a female threaded portion formed on the inner periphery of the threaded bush is connected to one male threaded portion of the second assembled component by a male threaded portion formed on the outer periphery of the threaded bush. Are screwed into female screw portions formed in one of the mounting holes of the first assembled component, and a thread bush tightening operation for tightening the thread bush is started. Next, after the tightening torque by the preceding one thread bush tightening operation becomes the tightening torque set value in a state where each of the threaded screw portions has reached the effective screw portion region by the progress of the tightening operation, or After the time required from the start of the preceding thread bush tightening operation to the time when each of the threaded screw portions reaches the effective screw region by the progress of this tightening operation, the first and second sets are started. A subsequent other thread bushing operation for the attached part is disclosed.

For this reason, the subsequent thread bush tightening operation is performed when the respective threaded screw portions reach the effective screw portion region due to the progress of the preceding thread bush tightening operation, and therefore, the first assembly component on the subsequent side. The center line of the assembling hole and the axis of the thread bush do not coincide with each other, and the external thread of the thread bush is screwed into the female thread of the assembling hole of the first assembling part in a regular state. The thread bush tightening operation is performed with high accuracy. Furthermore, since the two thread bush tightening operations are performed simultaneously with a slight time lag, the tightening operation is performed in a short time, and the cycle time is shortened.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 2 shows a case in which the thread bush tightening method according to one embodiment of the present invention is applied to assembling an upper arm shaft to an upper arm constituting a suspension of a vehicle such as an automobile.

First, before describing the method of the present invention, an assembling structure of an upper arm shaft to an upper arm will be described with reference to FIGS. 1 and 2. In FIG.
The upper arm 2 is an upper arm shaft as a second assembling part. A pair of assembling holes 3, 3 are formed at both ends of the upper arm 1, and a female screw portion is formed on an inner periphery of each of the assembling holes 3. 4 are formed. On the other hand, a pair of male screw portions 5, 5 are formed at both ends of the upper arm shaft 2, and each male screw portion 5 is inserted into each mounting hole 3 of the upper arm 1 at a predetermined interval from the female screw portion 4. ing.

6, 6 are two cylindrical thread bushes,
A female thread 7 is formed on the inner periphery of each thread bush 6, and a male thread 8 is formed on the outer periphery. The respective thread bushes 6 are inserted into the respective mounting holes 3 of the upper arm 1 by inserting the respective male screw portions 5 of the upper arm shaft 2 so that both are supported by a support (not shown).
The female screw 7 is inserted into each of the mounting holes 3 of the upper arm 1 and the male screw 5 of the upper arm shaft 2.
The male screw portion 8 is connected to the female screw portion 4 of the upper arm 1,
The upper and lower nut runners 9 and 9 are screwed and tightened by the operation of the pair of upper and lower nut runners 9, whereby the upper arm 1 and the upper arm shaft 2 are assembled. In FIG. 1, reference numeral 10 denotes a dust cover.

Next, a thread bush tightening method according to the present embodiment will be described. First, as shown in FIG.
The two male threads of the upper arm shaft 2 are inserted into both mounting holes 3 and 3.
With both of the nut runners 9, 9, two thread bushes 6, 6,
Is held in engagement.

Next, the two nut runners are controlled by a command from the control device 11.
One of the nut runners 9 (upper in FIG. 2) is operated, and the thread bush 6 engaged with and held by the nut runner 9 is inserted into one of the upper holes 1 of the upper arm 1 (upper in FIG. 2). And the female thread 7 of the thread bush 6 is connected to the male thread 5 on one side (upper side in FIG. 2) of the upper arm shaft 2, and the male thread 8 of the thread bush 6 is connected to the female thread 4 of the upper arm 1. The thread bush 6 is tightened by screwing. Thereby, the upper arm 1 and the upper arm shaft 2
Is started (the upper side in FIG. 2). During the thread bush tightening operation, a tightening torque by the one nut runner 9 is detected by a torque detector 12, and this detection signal is transmitted to the control device 11.
And compares it with the tightening torque set value preset and stored in the control device 11. This tightening torque set value is set at point A in the characteristic diagram showing the relationship between the tightening torque and the time in FIG. 3 at the time when each screwed screw portion has reached the effective screw region. By the way, in FIG.
The solid line indicates the preceding one (upper in FIG. 2)
The dashed line indicates the tightening torque of the nut runner 9 on the other side (lower side in FIG. 2).
, Respectively. Further, T ₁ is the peak value of the external thread portion 8 of the thread bushing 6 penetrates the female screw portion 4 of the assembly bore 3 of the upper arm 1, T ₂ is a bottom value thread bush 6 is seated, T ₃ after sitting Is a predetermined torque value, which is the tightening completion point.

Thereafter, when the tightening torque of the preceding one thread bush tightening operation reaches a set value (point A),
The other nut runner 9 is actuated by an operation command from the control device 11 to the other (lower in FIG. 2) nut runner 9, and the other (lower in FIG. 2) sled follows in the manner described above. Start the bush tightening work. Even during the thread bush tightening operation, the tightening torque by the other nut runner 9 is detected by the torque detector 13, and this detection signal is input to the control device 11.

Thereafter, when the tightening torque of both the nut runner 9,9 reaches _three point T in the characteristic diagram of Figure 3, the both nut runner 9,
9 is stopped by a command from the control device 11, and the thread bush tightening operation is terminated.

As described above, in the present embodiment, first, in a state where the pair of male screw portions 5, 5 of the upper arm shaft 2 are respectively inserted into the pair of mounting holes 3, 3, of the upper arm 1, one (upper side in FIG. 2) By the operation of the nut runner 9, the thread bush 6 is inserted into the one of the upper arms 1 (upper side in FIG. 2), and the female thread portion 7 of the thread bush 6 is inserted.
To one of the upper arm shafts 2 (upper side in FIG. 2)
The thread for tightening the thread bush 6 by screwing the male thread 8 of the thread bush 6 to the female thread 4 formed in the mounting hole 3 on one side (the upper side in FIG. 2) of the upper arm 1. Start the bush tightening work. Then, the torque detector 12 detects the tightening torque by the preceding one thread bush tightening operation, compares the torque with a characteristic diagram by the control device 11, and after the tightening torque reaches a set value (point A), The other (the lower side in FIG. 2) thread bush tightening operation for the first and upper arm shafts 2 is started in the manner described above.

From this, each of the threaded screw portions of the succeeding (lower side in FIG. 2) tightening operation is made effective by the progress of the preceding (upper side in FIG. 2) thread bushing operation. This can be performed at the stage when the outer region is reached, so that the center line of the assembling hole 3 of the rear upper arm 1 does not coincide with the axis of the thread bush 6, and the external thread portion 8 of the thread bush 6 is eliminated. Is screwed into the female screw portion 4 of the mounting hole 3 of the upper arm 1 in a regular state, so that the thread bush tightening operation can be performed with high accuracy. Further, the two thread bush tightening operations can be performed simultaneously with a slight time lag, so that the tightening operation can be performed in a short time and the cycle time can be reduced.

In the above-described embodiment, the tightening torque of the subsequent thread bushing tightening operation by the preceding one thread bushing tightening operation causes the respective threaded screw portions to reach the effective screw portion region as the tightening operation progresses. It is performed after the tightening torque reaches the set value (point A) in the tightened state, but is not limited to this. For example, the time from when the thread bush tightening operation is started until the tightening torque reaches the set value (point A) Empirically in advance, after the time required for each of the threaded screw portions to reach the effective screw portion region by the progress of this tightening operation from the start of the preceding thread bush tightening operation has elapsed. Alternatively, it is also possible to adopt the following other thread bush tightening operation. Also in this case, the same operation and effect as those of the above embodiment can be obtained.

Further, in the above embodiment, the case where the present invention is applied to the assembling of the upper arm shaft to the upper arm constituting the suspension of the vehicle such as an automobile has been described.
It can be applied to other parts assembling.

(Effects of the Invention) As described above, according to the method of the present invention, a first mounting component having a female female part in each of a pair of mounting holes formed at both ends, and a pair of male screw portions at both ends. When assembling the second assembling part with two thread bushes each having a female screw part on the inner periphery and a male screw part on the outer periphery,
One thread bush tightening operation for the first and second assembled parts is started. Next, after the tightening torque by the preceding one thread bush tightening operation becomes the tightening torque set value in a state where each of the threaded screw portions has reached the effective screw portion region by the progress of the tightening operation, or After the time required for each of the threaded screw portions to reach the effective screw portion region has elapsed due to the progress of this tightening operation after the start of the preceding one thread bush tightening operation, the succeeding other thread bush tightening operation To start. Therefore, there is no phase shift in which the center line of the mounting hole of the subsequent first mounting component and the axis of the thread bush do not coincide with each other, and each screw portion is screwed in a regular state, thereby tightening the thread bush. Work can be performed accurately and in a short time.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is an enlarged sectional view showing a part of an assembly portion of an upper arm and an upper arm shaft, and FIG. 2 is a schematic configuration diagram of a fastening device. FIG. 3 is a characteristic diagram showing the relationship between the tightening torque and time. DESCRIPTION OF SYMBOLS 1 ... Upper arm (1st assembly part) 2 ... Upper arm shaft (2nd assembly part) 3 ... Assembly hole 4,7 ... Female thread part 5,8 ... Male thread part 6 ... Thread bush

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B23P 21/00 303 B23P 19/06 B25B 23/14 610-640 B60G 7/02

Claims (1)

(57) [Claims] A first assembly component having a female thread portion in each of a pair of assembly holes formed at both ends, and a second assembly component having a pair of male thread portions at both ends. In a state where the male threads of the second assembly are inserted into the assembly holes of the assembly, two thread bushes each having a female thread on the inner periphery and a male thread on the outer periphery are connected to the first assembly. The female thread of each thread bush is screwed into the male thread of the second component, and the male thread of each thread bush is threaded into the female thread of the first component. A first thread bush tightening operation for the first and second assembled parts is started, and then the tightening torque by the preceding one thread bush tightening operation is determined by the following method. After the tightening torque has reached the set screw torque value in a state where each of the threaded screw portions has reached the effective screw portion area by the progress of the mounting operation, or after starting the preceding one thread bush tightening operation, this tightening operation is started. A method for tightening a thread bush, characterized in that, after a lapse of time required for each of the threaded screw portions to reach the effective screw portion region as the process proceeds, a succeeding other thread bush tightening operation is started.