JPH0310596Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a time switch in which a drive source such as a motor is attached to the outside of the case.

[Prior art]

Conventionally, when a pinion, etc. is fixed to the output shaft of a type of motor that holds the output shaft with a bushing fixed to the case, and the motor is fixed to the case of a time switch, the bushing fits into the through hole of the case.The output is output at the time switch. The following methods are used to secure the pinion to the shaft.

Press-fit or adhesively fix the pinion to the output shaft.

Insert the output shaft and pinion hole using a D-cut, etc. to prevent rotation, and use an E-ring, etc. to prevent it from coming out.

The pinion is integrally molded on the output shaft.

However, the above method has the following drawbacks.

Since a large external force is applied to the inside of the motor for press-fitting, consideration must be given to strength. In addition, with resin pinions, etc., the fixation to the output shaft becomes loose due to stress relaxation due to changes over time, and the output shaft needs knurling. Furthermore, if the outer diameter of the pinion is larger than the outer diameter of the bush, the pinion must be press-fitted onto the output shaft after fixing the motor to the time switch case, resulting in poor workability.

This requires extra parts such as E-rings and additional installation work.

In this case, it is necessary to make the pinion outer diameter smaller than the output shaft outer diameter, which is a major design constraint.

Furthermore, with either method, if the pinion is located far from the bush, the effects of radial play or inclination of the output shaft will be exacerbated, and the engagement with the time switch gear that meshes with the pinion will become extremely unstable. Therefore, in practice, the pinion had to be placed near the bushing. In addition, as time switches have become smaller and thinner in recent years, the gear train etc. have become denser and the gaps between the gears are smaller, and there is a greater demand for pinion thrust position accuracy.However, with conventional fixing methods, various tolerances are There are drawbacks such as lack of accuracy due to accumulation.

[Purpose of invention]

In view of the above-mentioned drawbacks, the present invention solves the above-mentioned drawbacks by forming and connecting an engaging portion that engages the other end of the drive gear of the time switch case and the output shaft of the drive source so as to rotate together, and by a simple assembly process. The purpose is to propose a time switch that solves the problem.

[Structure of the idea]

In the present invention, a support part for supporting one end of a drive gear is provided on one side of a case housing a timer cam, a reduction gear train, etc., and a through hole through which an output shaft of a drive source passes is formed in the other case. The other end of the drive gear is formed with an engaging portion that engages with the output shaft so as to rotate together, and the drive source is attached to the case to connect the output shaft and the drive gear to perform drive transmission. There is a particular thing.

〔Example〕

The present invention will be explained below with reference to illustrated embodiments. The time switch is located in the lower case 1 in Figures 1 to 3.
and an upper case 2 are combined to form a housing shape, and a drive source 3 using, for example, a motor is attached to the outside of the lower case 1 with a bag-shaped notch 1a and screws 10.

When the drive source 3 is attached to the lower case 1, the bush 4 of the drive source 3 is fitted into the through hole 1b of the lower case 1, and the output shaft 5 of the drive source 3 and the drive gear 6 are connected to the respective engaging portions 5a. , 6a so that they rotate together. The engaging portions 5a and 6a on the output shaft 5 side are formed in a D-cut shaft, and the engaging portion 6a on the drive gear 6 side is formed in a D hole, respectively.

One end of the drive gear 6 is formed in a recess 6b and is fitted and supported on the outside of the annular convex support 2a of the upper case 2. The drive gear 6 includes a cam gear 7
are engaged with each other, and are arranged so that even if the output shaft 5 is pulled out from the drive gear 6, it will come into contact with the brim-shaped cam plate 7a of the cam gear 7. The cam gear 7 is fitted onto the main shaft 11 so as to be slidable in the axial direction, and is biased downward in FIG. 1 by a coil spring 12. A timer cam 8 is press-fitted into one end of the main shaft 11, and the lower cylindrical portion 8a of the timer cam 8 is fitted into the outer periphery of the annular recess 1c of the lower case 1, thereby positioning one end of the main shaft 11. The other end of the main shaft 11 is the upper case 2
It protrudes to the outside from the through hole 2b. The cam gear 7 is pressed against the timer cam 8 by the coil spring 12, and has two triangular chevron-shaped protrusions 7b at different positions from the center of the bottom surface of the cam gear 7, and two triangular protrusions 7b at different positions from the center of the top surface of the timer cam 8. The rotation of the output shaft 5 is caused by the engagement of the triangular chevron-shaped protrusion 8b.
a, 6a, the drive gear 6, and the cam gear 7 to the timer cam 8.

The tip of a lever 14, one end of which is fitted onto a support shaft 13 implanted in the case 1 or 2, is urged into contact with the outer peripheral cam surfaces of the cam gear 7 and the timer cam 8 by the spring pressure of the contact piece 15. , a contact piece 15 and other contact pieces 16 and 17 are fixed to the lower case 1.

When the time switch is configured as described above,
The output shaft 5 and the drive gear 6 are connected to the bush 4 of the drive source 3.
The engaging portions 5a and 6a are engaged and connected by aligning and fitting into the through hole 1b of the lower case 1, and the number of parts is small and assembly is easy.
The shortcomings of are eliminated.

Furthermore, since the drive gear 6 is supported by the engaging parts 5a, 6a, the support part 2a of the upper case 2, and the recessed part 6b, the output shaft 5 may have radial play.
Even if the drive source 3 is attached to the case 1 with the drive source 3 tilted, or the teeth 6c of the drive gear 6 are on the opposite side away from the drive source 3, the engagement between the drive gear 6 and the next gear will not be adversely affected. Stably interlocked.

The positional accuracy of the teeth 6c of the drive gear 6 in the thrust direction is determined by controlling the accuracy of the length of the shaft 6d from the teeth 6c to the end surface on the side of the engaging portion 6a, and on the axis from the teeth 6c to the end surface on the side of the recess 6b. This is done by controlling the accuracy of the length of the part 6e and controlling the accuracy of the length of the bush 4,
When the time switch is used with the drive source 3 at the bottom, the accuracy of the length of the shaft portion 6e and the bush 4 is determined, and when the time switch is used with the drive source 3 at the top, the length of the shaft portion 6d is determined. Positional accuracy is achieved through dimensional accuracy, and it can also be applied to a gear train of a time switch in which a plurality of gears are stacked at high density on one shaft (not shown).

The engaging portions 5a, 6a may have a rectangular shaft and a rectangular hole.

FIG. 4 and the following are other embodiments, in which the engagement portion 5a of the output shaft 5 is engaged with the other end engagement portion 9a of the drive gear 9 in FIG. The pin-shaped support portion 2c of the upper case 2 is fitted.

The other end engaging portion 9a of the drive gear 9 in FIG. 5 is formed into a shaft shape, and the engaging portion 5a of the output shaft 5 is formed into a hole shape and is engaged therewith. One end of the drive gear 9 is a tenon 9
c and is fitted into the mortise hole 2d of the upper case 2. When the output shaft 5 is pulled out, the drive gear 9 is connected to another gear (not shown) so that the tenon 9c is connected to the tenon hole 2d.
It is placed so that it does not fall off.

[Effect of idea]

Since the present invention is configured as described above, the output shaft and the drive gear can be easily connected, improving assembly efficiency, and there is no restriction due to the outer diameter of the bushing or output shaft.
The radial position accuracy of the drive gear has been improved, so that the drive gear and the next gear mesh stably, and the position accuracy of the drive gear in the thrust direction has been improved, resulting in a high-density gear gap. It is possible to provide a time switch that has excellent practical effects, such as being compatible with switches.

[BRIEF DESCRIPTION OF THE DRAWINGS] The drawings show one embodiment of the present invention, and FIG. 1 is a cross-sectional side view of the main part of a time switch with the case shown in cross section, and FIG. 2 is a cross-sectional side view of the main part of the time switch. A cutaway plan view, Figure 3 is a back view of the drive source, Figure 4
5 and 5 are sectional side views of main parts of other embodiments, respectively. DESCRIPTION OF SYMBOLS 1, 2... Case, 1b... Through hole, 2a... Support part, 3... Drive source, 5... Output shaft, 5a6a, 9a
...Engagement part, 6, 9... Drive gear, 8... Timer cam.