JPS5932758Y2 - Cam that transmits driving force with a flexible shaft - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a cam that is transmitted and driven by a flexible shaft.

Various cams have conventionally been used as means for converting rotation into linear motion, but there are various cases in which there are mechanical limitations in the arrangement of the cam and a drive source such as a motor, which often causes difficulties.

By using a flexible shaft to transmit and drive the cam, the arrangement of the drive source such as a motor and the cam can be freely set, the mechanism can be simplified, and the machine in which it is incorporated can be made smaller.

However, since the flexible shaft has elasticity, the input rotation amount does not accurately correspond to the rotation amount of the cam, resulting in a large error, so it has not been used much in the past.

Generally, the difference in rotation amount due to a flexible shaft has a constant value depending on the length of the flexible shaft, bending radius, bending angle, and transmission force.

Therefore, it is possible to set the flexible shaft in advance so that the difference in rotation amount of the flexible shaft that causes this error has a constant value, but strictly speaking, the bending radius and bending angle are determined by In addition, the transmission force required when a load is applied to the cam and it is operated is determined, so it cannot be set at the time of design or manufacturing.

However, when the flexible shaft is actually installed and used, these amounts naturally become constant values, so if this constant rotation amount difference can be corrected for the cam position, it will be effective as a cam with less error. It can be used for.

In view of the above points, this invention finds errors when using a flexible shaft, and provides a cam with a mechanism for correcting the errors.The cam shaft and input shaft are connected by a flexible shaft, and the connection an engaging portion that removably engages one of the portions;
The present invention is characterized in that the phase difference between the camshaft and the input shaft can be freely adjusted by disengaging the engagement portion and rotating the flexible shaft by an amount corresponding to the phase difference.

This invention will be explained below based on the embodiments shown in the drawings.

In FIG. 1, 1 is a rotating cam, and 2 is a cam follower (not shown) on the outer periphery of the cam 1 that is constantly in contact with a spring or the like and moves up and down.

3 is a nut which is fixed so that the cam 1 cannot be pulled out from the camshaft 6 in the axial direction after the cam 1 is connected to the camshaft 6 with a key 9.

Reference numeral 4 denotes a case in which the camshaft 6 is rotatably housed via bearings 5, 5, and is fixed to the main body, etc., although not shown.

13, 13 are spacing pieces that maintain the distance between the inner and outer rings of the bearings 5, 5.

One end of the camshaft 6 is fixed to the cam 1 as described above, but the other end is a large diameter part 61 with a hole drilled in the 1st axis, and a female spline or equivalent is installed in the inner diameter part. A plurality of grooves are engraved to form an engaging portion 63 that engages with the flexible shaft, as will be described later.

Further, a screw 62 is screwed onto the outer periphery of the large diameter portion 61, and the spring tube 14 is screwed into the screw 62.

Reference numeral I designates a connecting shaft, on one end of which a flexible shaft 10 is fixed concentrically by brazing or by staking or caulking, and the other end is provided with a stepped portion 72 to form a large diameter portion, and the camshaft 6 engages with the flexible shaft 10. A similar engaging portion 71 is provided with protrusions corresponding to male splines or multiple grooves so as to be freely engageable and detachable from the mating portion 63 in the axial direction.

8 is a compression spring, one end of which is attached to the spring tube 14 and the other end of which is attached to the stepped portion T2 of the connecting shaft I, constantly applying a compressive force to the connecting shaft I.

The strength of the compression spring 8 can be easily adjusted by changing the position of the spring tube 14.

The flexible shaft 10 is made by twisting steel wires, and an input shaft 12 is concentrically fixed to the opposite side to which the connecting shaft 7 is attached by brazing or caulking.

Reference numeral 11 denotes a flexible tube, which is made of a spiral tube case or a cylinder made of flexible material, and is fitted onto the outside of the flexible shaft 10 with a gap.

As mentioned above, on the inner circumference of one end of the camshaft 6, multiple grooves of the same shape are formed parallel to the axis and at equal intervals to form the engaging portion 63, which is fitted into the connecting shaft I with a slight clearance. The engaging part 7 is slidable in the axial direction and has protrusions corresponding to the multiple grooves so that the rotational force is transmitted and the engagement part 7 is slidable in the axial direction.
1, so if the connecting shaft T is moved to the right in FIG.
The engagement with is released.

Although the connecting shaft I is always pushed in the direction of the camshaft 6 by the compression spring 8, a margin is provided for the compression amount of the compression spring 8 so that the engagement between the two can be easily released manually.

Now, when the input shaft 12 is connected to a drive source such as a motor and the cam 1 is driven, the flexible shaft 10 is elastically deformed according to the transmitted force, causing a difference in rotation amount and causing a rotation delay in the cam 1. arise.

At this time, pull the connecting shaft I while bending the flexible shaft 10,
The rotation amount error can be corrected by disengaging the coupling shaft 1 from the camshaft 6, rotating the coupling shaft 1 to restore the rotational delay, shifting the relative position, and engaging the camshaft 6 again.

FIG. 2 shows an embodiment in which a coupling mechanism (retaining portion) is provided on the input shaft side.

In the figures, the same components are given the same reference numerals.

One end of the flexible shaft 10 is fixed to the camshaft 6a by brazing or caulking, and the other end is fixed to the connecting shaft I by brazing or caulking.

One end of the input shaft 12a constitutes a large diameter portion 121a, similar to the camshaft 6 shown in FIG.
The retaining portion 122a is configured to be releasably engaged with the engaging portion 11 of the connecting shaft 1 in the axial direction.

To correct the error, as in the case of FIG. 1, bend the flexible shaft 10, compress the compression spring 8, pull the connecting shaft 1, and remove the connection with the input shaft 12a while correcting the rotational delay. Rotate the connecting shaft 7 by the same amount, shift the relative position, and connect the input shaft 12 again.
What is necessary is to engage with a.

By correcting the error in this way, the flexible shaft 10
A force is applied in the direction of the rotational force, and the phases match,
Thereafter, the rotation of the input shaft 12 or input shaft 12a will be directly transmitted to the cam 1 via the flexible shaft 10.

As stated above, in both the embodiments shown in Fig. 1 and Fig. 2, the present invention corrects the rotation amount error on the cam 1&+, the housing fixed in the actual use condition that requires precision, and the drive side. Therefore, there is no need to calculate the amount of correction on the load side in advance or to measure it using a measuring device.

In addition, since the present invention utilizes the flexibility of the flexible shaft 10 for error correction work, there is no need to remove the shaft or use tools to remove it, which would be required if a hard shaft was used in the past. , workability is also extremely good.

As mentioned above, according to the present invention, it is possible to provide a cam that uses a flexible shaft, is easy to modify, and has few errors, and is effective in simplifying and downsizing the mechanism using the cam.

In the above description, the engaging portion is a spline or multiple grooves and protrusions, but serrations or key fitting may also be used as long as it can move in the axial direction and transmit rotational force.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the present invention, FIG. 2 is a sectional view showing another embodiment, and FIG. 3 is a sectional view taken along line AA in FIG. In the figure, 1 is a cam, 2 is a chi follower, 4 is a case, 6 is a cam shaft, 1 is a connecting shaft, 8 is a compression spring, 10 is a flexible shaft, 12 is an input shaft, 63.71 122a is an engaging part.

Claims (1)

[Scope of utility model registration request] A camshaft 6 with a cam 1 provided at one end, a case 4 rotatably supporting the camshaft 6, an input shaft 12 rotatably driven by a drive source, and the input shaft 12 and the camshaft 6. A flexible shaft 10 to be connected, a coupling portion connected to either the camshaft 6 or the input shaft 12 provided at one end of the flexible shaft 10, and the input shaft provided at the other end of the flexible shaft 10. 12 or the camshaft 6, and the phase difference between the input shaft 12 and the camshaft 6 can be freely adjusted via the flexible shaft by leaving the retaining part. A cam that transmits driving force with a flexible shaft that can be adjusted.