JPS6116444Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cam device that converts linear motion and rotational motion.

For example, in a mechanism that uses a fluid pressure cylinder as an actuator and converts the linear motion of the piston into rotational motion to open and close a valve, the axial thrust of the piston rotates a cam, and this cam is fixed. Many valves have a structure in which a spiral or spherical valve body is rotated by the rotation of the output shaft. In converting the axial thrust of the piston into rotation of the output shaft, the distance between the output shaft placed across the cylinder tube and the pin provided on the piston that contacts and engages with the cam is made as large as possible to create a small size. It goes without saying that it is desirable that the actuator also be able to obtain a large output torque.

However, the output shaft is disposed across the cylinder tube, and the cam is fixed to the output shaft and built into the cylinder tube, and is engaged with the pin, so assembly is extremely complicated. had to be moved closer to the output shaft. Additionally, in order to compensate for the lack of output torque, attempts have been made to install two pistons between the output shaft and engage a cam with each pin to move the pistons linearly in opposite directions, but the structure inevitably becomes more complex.

This project improves the assembly structure of the cam and output shaft,
The cam can be easily fixed to the output shaft built into the cylinder, and a large output torque can be obtained.

Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view of the output shaft and the cam. The output shaft 1 has parallel flat surfaces 2, 2 and stepped portions 3, 3 cut at symmetrical positions across the central axis, and an annular groove 4 with a small diameter on the side opposite to the stepped portions 3, 3 of the flat surfaces 2, 2. is provided. The cam 5 is made in the shape of a disk, and has a groove 6 that is open to the outer peripheral surface and both surfaces and has a width equal to the distance between the flat surfaces 2, 2. The center of the cam 5 is formed on both ends of the groove 6. Arc-shaped notches 7, 7 having a diameter equal to the diameter of the output shaft 1 are provided at an appropriate depth from one surface. An O-ring 8 is fitted into the annular groove 4 of the output shaft 1, and the groove 6 is connected to the flat surfaces 2, 2 of the output shaft 1.
and push the cam 5 into the annular groove 4 (see Fig. 2), and when it is pushed to the end of the groove 6, move it in the axial direction of the output shaft 1, and move the step 9 at the bottom of the notch 7, 7.
9 and the stepped portions 3, 3 of the output shaft 1 are assembled together.

Both sides of the groove 6 of the cam 5 form cam surfaces 10, 10, and these cam surfaces 10, 10 contact the parallel planes 2, 2 of the output shaft 1 to integrate the cam 5 and the output shaft 1. The circular arc surfaces of the notches 7, 7 are in contact with the outer circumferential surface of the output shaft 1.

Figures 4 and 5 show an example in which the cam device of the present invention is used in an actuator for opening and closing a valve. A pin 15 of a piston 14 is engaged with a groove 6 of a fixed cam 5.
The piston 14 has a split groove 16 through which the output shaft 1 is inserted and a split groove 17 perpendicular thereto through which the cam 5 is inserted, and a pin 15 is provided in the split groove 17 through which the cam 5 is inserted. In FIG. 4, the piston 14 is fitted into the cylinder tube 11 from the right side, and the cam 5 is inserted into the groove 17 from the left side to be fixed to the output shaft 1, or the piston is fitted with the cam 5 inserted into the groove 17 in advance. 14 into the cylinder tube 11 and fix the cam 5 to the output shaft 1. Next, the piston 14 and the cam 5 are operated to engage the pin 15 in the groove 6, and the cylinder tube 1
Both ends of 1 are covered with lids 12 and 13. Cylinder tube 11
When the piston 14 is linearly moved by supplying and discharging the working fluid, the cam 5 is rotated by the pin 15, and the output shaft 1 is also rotated to rotationally drive the valve body of the valve (not shown).

Note that the output shaft 1 may be fixed at a position offset from the center of the cam 5 by making the groove 6 longer, and in this case, the distance between the output shaft 1 and the pin 15 can be made larger than the radius of the piston 14. Further, it goes without saying that the outer shape of the cam 5 is not limited to a disk shape.

As described above, in this case, the output shaft is cut to provide parallel planes, and the cam is provided with grooves of equal width between these planes, so that the output shaft can be placed in a blind place such as inside the cylinder. Not only can the cam be easily assembled by fitting the groove into the flat part and pushing it, but also this parallel flat part allows the cam and the output shaft to rotate together, causing them to rotate together. Let it happen. Since the arcuate surfaces of the notches on both sides of the groove are in contact with the outer circumferential surface of the output shaft, this portion acts as a retainer and stably fixes the cam to the output shaft. In addition, the groove of the cam engages the pin of another driving part or driven part fixed to the output shaft to convert between linear motion and rotational motion, so the structure of the cam and output shaft is simple and the number of parts is small. Since assembly can be easily performed even in a blind area, assembly is possible even if the distance between the pin and the output shaft is increased, and therefore a large torque can be applied to the output shaft.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of the output shaft and cam, Fig. 2 is a partial vertical cross-sectional view showing the assembly situation, Fig. 3 is a partial vertical cross-sectional view of the cam device according to the present invention, and Fig. 4 shows an example of use. The cross-sectional view, FIG. 5, is a cross-sectional view taken along the line XX in FIG. 4. 1...Output shaft, 2...Plane, 3...Step, 5...
...Cam, 6...Groove, 7...Notch, 9...Step,
10...Cam surface.

Claims (1)

[Scope of utility model registration request] an output shaft 1 provided with parallel planes 2, 2 formed by cutting at symmetrical positions across the central axis;
A groove 6 having a width equal to the distance between the planes 2 and 2 and open to the outer peripheral surface and both surfaces is provided.
The cam 5 has arcuate notches 7, 7 having the same diameter as the output shaft 1 at an appropriate depth from one surface on both sides of the terminal end of the cam 5. A cam device in which a cam 5 is assembled to an output shaft 1 such that the arcuate surfaces of the notches 7, 7 are in contact with the outer peripheral surface of the output shaft 1.