JPS6238291Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a timer speed reduction mechanism that is easy to manufacture and assemble, and that can reduce the size and weight of the timer.

Conventionally, among this type of speed reduction mechanism, in a gear type speed reduction mechanism that reduces speed by meshing a worm 1 and a worm gear 2 as shown in FIG. It is difficult to manufacture the worm gear 2 due to the helix angle, and special consideration must be taken when assembling it, which causes a decrease in timer productivity. The meshing relationship and shaft support position of the worm gear 1 and the worm gear 2 are restricted, resulting in an increase in the size of the entire timer.

The present invention proposes a timer speed reduction mechanism that eliminates the drawbacks of the conventional mechanisms described above, can be easily manufactured and assembled, and can be made smaller and lighter, and can be provided at a lower cost.

That is, the present invention provides a worm-based reduction unit for a timer reduction mechanism that performs multi-step reduction by having a plurality of worms configured with the same helix angle and a spur gear in place of a worm gear that meshes with the worm. The spur gears of each stage except the final stage and the worm of the next stage are respectively fixed on the same axis, and each stage of the reduction section except the final stage meshes with the axial center of the worm. The gist of the invention is a speed reduction mechanism for a timer, characterized in that the shaft center of a spur gear is meshed with the shaft center of the spur gear at an angle complementary to the helix angle of the worm from a position where the two are parallel.

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings. Fig. 2 shows a front view of a timer using the deceleration mechanism of the present invention. A drive motor 4 is attached to the bottom. The drive motor 4 has a worm 5 fixedly attached to its drive shaft, and a spur gear substituted as a worm gear 6 meshes with the worm 5 to transmit the power of the drive motor 4 to the worm gear 6 via the worm 5. It's like this. The worm gear 6 is fixed to a shaft 8 supported between vertical partition frames 7, 7 of the case 3, and rotates in synchronization with a worm 9 having the same helix angle as that of the worm 5 fixed on the same axis. It is designed to do so. As shown in FIG. 3, the worm 5 and the worm gear 6 are arranged so that the directions of the tooth traces of the worm 5 and the tooth traces of the worm gear 6 almost match. is supported by the worm 5 at an angle of torsion angle α. That is, in FIG. 2, the shaft 8 is the drive motor 4 to which the worm 5 is fixedly attached.
The worm 5 is attached to the vertical partition frames 7, 7 so as to be inclined by the torsion angle α with respect to a straight line perpendicular to the drive shaft of the worm 5, in other words, a straight line parallel to the horizontal plane. Reference numeral 10 denotes a worm gear substituted with a spur gear that meshes with the worm 9, and the rotating shaft 11 is aligned with respect to the shaft 8 of the worm 9 so that the direction of the tooth trace of the worm gear almost matches the direction of the tooth trace of the worm 9. The rotating shaft 11 is arranged at an angle corresponding to the twist angle α, and as a result, the rotation shaft 11 is arranged perpendicular to the horizontal line. 12 is the worm gear 1
This worm 12 is a worm installed coaxially with 0.
Worm gear 1 whose tooth trace direction almost matches
A spur gear 3 is meshed with the worm 12, and 14 is the worm gear 12 disposed coaxially with the worm gear 13.
The rotation shaft 15 of the worm has the same helix angle as that of the worm 12, and its rotating shaft 15 is inclined with respect to the horizontal line by the helix angle of the worm 12, and the direction of the tooth trace is orthogonal to the horizontal line. 16 is the worm 1
This is a spur gear that meshes with the worm 14 and the spur gear 16, and the meshing between the worm 14 and the spur gear 16 becomes the final stage of the worm speed reduction section. This final stage spur gear 16 is connected to a transmission member on the output side, which will be described later. 17 is a pinion provided coaxially with the spur gear 16, 18 is an output gear meshing with the pinion 17, and 19 is a disc-shaped cam provided coaxially with the output gear 18, as shown in FIG. A recess 20 is formed in a part of the circumference, and 21 is a time setting dial provided coaxially with the cam 19. Reference numeral 22 denotes a lever whose base part is rotatably supported, and a protruding part 23 is provided on the upper part of the lever so that it can be inserted into the recess 20 formed in the cam 19, and the protruding part 23 is normally inserted into the recess 20. On the other hand, when setting the time using a dial, which will be described later, the protrusion 23 is brought into contact with the circumferential surface of the cam 19 and rotated against the force of a spring (not shown). In addition, 24, 25, 26 in Figure 4
are terminals for a normally closed contact, a common contact, and a normally open contact, respectively; 27 is a resilient actuating piece attached to the common contact terminal 25; the tip thereof is normally in contact with the bent portion 28 of the lever 22 to form a normally closed contact; and the common contact are electrically connected, and the protrusion 23 of the lever 22 connects to the cam 1.
The normally open contact and the common contact are electrically connected while in contact with the peripheral surface of 29, 3.
0 and 31 are the respective contact points.

The speed reduction mechanism according to the present invention configured as described above operates as follows. That is, when the time is not set using the dial 21, the protrusion 23 provided on the lever 22 engages in the recess 20 of the cam 19.
In order to maintain the normal state between the bent portion 28 of the lever 22 and the operating piece 27 provided on the common contact terminal 25 as shown in FIG. 4, the common contact 30 and the normally closed contact 31 are in contact and electrically conductive. ing.

Next, when the dial 21 is rotated to set the time, the cam 19 provided coaxially with the dial 21 rotates in the same direction, and the engagement between the recess 20 and the protrusion 23 of the lever 22 is released, and the protrusion 23 contacts the circumferential surface of the cam 19, the lever 22 rotates counterclockwise in FIG. The common contact 30 and the normally open contact 29 are bent toward the normally open contact 29 due to the elasticity, and the common contact 30 and the normally open contact 29 are brought into contact and electrically connected.

Now, when the drive motor 4 is started in this state, the driving force is worm 5 - worm gear 6 - worm 9 - worm gear 10 - worm 1
2-worm gear 13-worm 14-spur gear 1
After passing through a worm reduction section consisting of four stages connected to 6, the signal is transmitted to the cam 19 via the pinion 17 and output gear 18, and the cam 19 is transferred to the output gear 18.
Rotate in sync with.

Then, as the rotational displacement of the cam 19 increases, the recess 20 formed in the cam 19 and the protrusion 23 of the lever 22 approach each other, and when a predetermined set time is reached, the protrusion 23 is moved into the recess 20. intervene. As the protruding portion 23 engages, the lever 22 returns to its original position due to the spring force, and the actuating piece 27, which had been bent by the bent portion 28 of the lever 22, returns to its original position and connects the common contact 30 to the normally open position. The contact with the contact 29 is broken and the electrical continuity between them is broken, while the common contact 30 and the normally closed contact 31 are brought into contact and electrical continuity is established between the two, as shown in FIG. restore the condition.

As described above, the present invention replaces the worm gear with a spur gear in a timer gear type reduction mechanism in which a worm and a worm gear are meshed with a part of the deceleration path. This method has the effect of providing an inexpensive timer since it can be manufactured rationally without requiring any special consideration in its assembly.

In addition, the present invention fixes the spur gear substituted for the worm gear coaxially with the worm, and makes the helix angle of the worm that meshes with the spur gear the same as that of the worm that is coaxially provided with the spur gear, and the worm and the worm gear that mesh with each other. Since the shaft is supported at an angle corresponding to the torsion angle of the worm, the shaft support position can be rationally designed by, for example, arranging two shafts with the spur gear and the worm coaxially fixed with their respective inclination directions opposite. This has the effect of making the timer smaller and lighter by effectively utilizing the shaft support space.

Furthermore, in this invention, only the final stage gear of the multi-stage gear train that constitutes the reduction mechanism is engaged with the spur gear, making it possible to engage the gears without rotating the cam, making it easy to assemble the final stage gear, cam, etc. There is an advantage that

[Brief explanation of the drawing]

Fig. 1 is a front view showing the main parts of the conventional example, Fig. 2 is a front view showing an embodiment of the present invention with a part cut away, and Fig. 3 shows the worm and worm gear of the present invention. FIG. 4 is a front view of essential parts showing a basic example of the engaged state, and FIG. 4 is a plan view seen from above of FIG. 2. 5, 9, 12, 14...Worm, 6, 10,
13... Worm gear.

Claims (1)

[Scope of utility model registration request] A worm made up of multiple sets of the same helix angle,
In the worm-based deceleration section of the timer deceleration mechanism that has a spur gear in place of the worm gear that meshes with the worm and performs multi-stage deceleration, the spur gear of each stage except the final stage of the deceleration part and the worm of the next stage. are fixed on the same axis, and in each stage of the speed reduction section except the final stage, the axis of the worm and the axis of the spur gear meshing with this worm,
A speed reduction mechanism for a timer, characterized in that the two are inclined from a parallel position by an angle complementary to the torsion angle of the worm and engaged with each other.