JPH0518059Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a screw and a device for tightening its lock nut.

[Conventional technology]

For example, in order to adjust the valve clearance of an engine's intake and exhaust valves, even if you adjust the amount of protrusion of the adjustment screw provided on the rocker arm and tighten it with a constant torque, the lock nut will not work properly when the adjustment screw is fixed with a lock nut. Since the tightening torque is larger, the adjusting screw rotates together with the lock nut, and the amount of protrusion of the adjusting screw changes.

For this reason, the adjuster screw was adjusted by skilled workers relying on their senses when tightening the lock nut, but this caused problems in adjustment accuracy, work efficiency, and variations.

In highly automated production lines, there are automatic adjustment machines that control the protrusion amount of the adjusting screw by reading the stroke of the supply/exhaust valve, or control the protrusion amount of the adjusting screw by using the thread pitch of the screw. Proposed.

[Problem that the invention attempts to solve]

However, the above-mentioned automatic adjustment machine is a large-scale device, and is difficult to use on a production line where many types of products are mixed.
It is unsuitable for production lines with low automation.

The object of the present invention is to provide a highly versatile hand-held screw and nut tightening device that prevents the adjuster screw from rotating together when tightening a lock nut.

[Means and actions for solving problems]

In the present invention, a nut socket is arranged around the screw bit, and the two are installed so that they can rotate forward and reverse independently, and a nut socket is provided in the drive system of the screw bit that slips during forward rotation and engages during reverse rotation. This screw and nut tightening device is equipped with a directional clutch, a one-way adjusting shaft stopper that locks the one-way clutch when it rotates in the forward direction, and a stopper adjustment screw that locks the one-way clutch in a state that absorbs backlash when it rotates in the reverse direction.

Rotate the screw bit forward and tighten the adjusting screw to the specified protrusion amount and to the specified torque.

To tighten the lock nut, with the screw bit engaged with the adjusting screw, fit the nut socket into the lock nut, and first rotate the screw bit in the reverse direction.

The one-way clutch attached to the drive system of the screw bit slips and is locked to the adjustment shaft stopper when the screw bit rotates in the forward direction, but when the screw bit rotates in the opposite direction, it connects and rotates slightly in the opposite direction. After it moves and absorbs the backlash of the transmission system, it is locked with the stopper adjustment screw to hold the adjustment screw in a locked state.

In this state, rotate the nut socket in the forward direction and tighten the lock nut. The co-rotation of the adjuster screw is stopped by a screw bit, and the tightening reaction force applied to the adjuster screw when the lock nut is tightened is received by the stopper adjustment screw, which changes the protrusion amount of the adjuster screw. Tighten the lock nut to secure the adjustment screw.

〔Example〕

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of the adjusting screw and lock nut tightening device.

Screw bit 1 with a minus (-) tip
A nut socket 2 is arranged around the screw bit 1, and a screw drive gear 4, 7 is connected to the screw bit 1.
is rotated by an air motor 8. The air motor 8 can rotate freely in forward and reverse directions, and the tightening torque can be regulated.

The nut socket 2 is movable in the axial direction of the screw bit 1, and projects slightly beyond the tip of the screw bit 1 when lowered in the direction of the arrow in the figure. This nut socket 2 is driven around the screw bit 1 via driving gears 3 and 6 by an air motor 9 which can freely rotate in forward and reverse directions and can regulate the tightening torque.

The screw drive gear 4 is connected to a one-way clutch 10 via a reverse rotation switching clutch 5, and the one-way clutch 10 is provided with a locking spring 11. The case is provided with an adjustment shaft stopper 12 and a stopper adjustment screw 15 that engage with and disengage from a protrusion provided at one end of the one-way clutch 10.

Reference numeral 14 denotes a switching cylinder for the switching clutch 5 during reverse rotation, which is used to loosen the adjusting screw and lock nut by rotating both the screw bit 1 and nut socket 2 in the reverse direction when the adjusting screw needs to be readjusted. , for releasing the clutch 5 by pushing the push rod 13. By disengaging the clutch 5, the screw drive gear 4 is separated from the one-way clutch 10 and the adjusting shaft stopper 12, allowing reverse rotation.

The reference numeral 20 indicated by a dashed line is a support for the screw bit 1 or the air motor 9, and the tightening operation part 21 and the case 16 shown in FIG.
Attached to 0.

Next, the operation of this device will be explained.

FIG. 2 is an enlarged perspective view of the one-way clutch and the adjustment shaft stopper, and FIG. 3 is an enlarged perspective view of the one-way clutch 1.
FIG. 2 is a cross-sectional view of the engagement portion between the adjustment stopper 12 and the adjustment stopper 12.

As shown in Figure 4, the adjusting screw S is used to adjust the valve clearance of the engine's intake and exhaust valves.
is adjusted and tightened to a constant torque, and a lock nut N is screwed into this, and the adjustment screw S is tightened and fixed so that the amount of protrusion L does not change. The installation of the adjusting screw S and the tightening and fixing of the lock nut N will be explained below.

With the screw bit 1 protruding from the nut socket 2 as shown in Fig. 1, rotate the screw bit 1 in the forward direction (clockwise rotation), and adjust the protruding amount L of the adjuster screw S to the support V such as the rocker arm.
Adjust to the specified length and tighten with a constant torque.
At this time, the clutch 5 is connected, the one-way clutch 10 is biased in the direction K in FIG. Since the one-way clutch 10 is in a slipping state, the shaft 5a rotates in the forward direction together with the screw bit 1.

When the screw bit 1 stops, the adjusting screw S whose protrusion amount L has been adjusted to a predetermined length is screwed in the direction of the arrow in the figure by forward rotation of the screw bit 1, as shown in Figure 5A. As a result, backlash d occurs between the groove of the adjusting screw S and the tip of the screw bit 1, and backlash also occurs in the transmission gear that drives the screw bit 1.

To fix the adjusting screw S in this state with the lock nut N, the nut socket 2 is lowered and fitted into the lock nut N while the screw bit 1 is retained in the groove of the adjusting screw S.

The air motor 8 is reversely rotated to reversely rotate the screw bit 1. As a result, the one-way clutch 10 is automatically connected to the shaft 5a, and the one-way clutch 10 is rotated counterclockwise in FIG. As a result, the play d between the groove of the adjusting screw S and the tip of the screw bit 1, the play between the hexagonal part of the nut socket 2 and the lock nut N, and the backlash of the transmission gear are absorbed (Fig. 5B). maintained in the state.

Next, the nut driving air motor 9 is rotated forward through the time delay valve to tighten the lock nut in the direction s in FIG. 3. The co-rotation that causes the adjusting screw S when the lock nut is tightened is stopped by the screw bit 1, which is held in a stopped state, as shown in FIG. 5B. Further, the reaction force R generated on the adjusting screw S when the lock nut N is tightened to the support V is received by the C surface of the protrusion of the one-way clutch 10 in contact with the stopper adjustment screw 15.

Therefore, co-rotation of the adjuster screw when tightening the lock nut based on backlash etc. is prevented, and the lock nut can be tightened without changing the adjusted protrusion amount of the adjuster screw.

The amount of absorption of the backlash is adjusted using the stopper adjustment screw 15.

In this embodiment, the screw bit 1 and the nut socket 2 are driven by an air motor, but it is of course possible to replace it with a DC or AC electric motor. Moreover, it can be used not only for adjusting the protrusion amount of the adjusting screw, but also for tightening general screws and their lock nuts.

[Effect of idea]

Since the present invention can prevent the screws from rotating together when tightening the lock nut, the accuracy of adjusting the screw protrusion amount is improved, work efficiency is improved, and a compact and highly versatile tightening device can be obtained.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an embodiment of the present invention, Fig. 2 is an enlarged perspective view showing the main parts of Fig.
4 is an explanatory diagram of an example of the adjusting screw, and FIG. 5 is an explanatory diagram of the adjustment screw attachment function. 1... Screw bit, 2... Nut socket, 3, 6... Nut socket drive gear, 4,
7... Screw bit drive gear, 5... Reverse switching clutch, 8... Air motor for screw bit drive, 9... Air motor for nut socket drive, 10... One-way clutch, 11... Lock spring, 12 ...Adjustment axis stopper, 15...
Stopper adjustment screw.

Claims (1)

[Scope of utility model registration request] A nut socket is arranged around the screw bit, and both are installed so that they can rotate forward and backward independently, and a one-way clutch is attached to the drive system of the screw bit, which slips when the screw rotates in the forward direction and engages when it rotates in the reverse direction. A screw and nut tightening device characterized in that it is provided with an adjusting shaft stopper that locks the one-way clutch when the one-way clutch rotates in the forward direction, and a stopper adjustment screw that locks the one-way clutch in a state that absorbs backlash when the one-way clutch rotates in the reverse direction.