JP2648867B2 - Drive system start / stop device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a starting and stopping device provided in a tool transfer device of a tool chain of a machine tool, a pallet transfer device of various mechanisms, an intermittent feed device of articles, and the like.

2. Description of the Related Art Generally, an electric or hydraulic servomotor is used as the start / stop device. However, this device has a quick start / stop function in order to improve the function of a device using the servomotor. And the accuracy of the stop position is required.

Problems to be Solved by the Invention: If the requirements for accurate positioning are satisfied and the above-mentioned requirements are met, not only the size of the device becomes large but also the device becomes extremely expensive.

Means for solving the problem: The present invention includes a point where the rotation speed of the output shaft is set to 0 in the speed change range, and increases the magnitude of torque that can be generated as the rotation speed of the output shaft decreases, A frictionless continuously variable transmission capable of generating a large torque when the rotation speed of the output shaft is close to 0, and one or a plurality of recesses provided on the periphery driven by the frictionless continuously variable transmission. With a cam disk,
A cam follower made to follow the peripheral surface of the cam disk, a transmission ring as a shifting element of the frictionless continuously variable transmission, and the cam follower interposed between the cam follower and a cam disk by a stop signal. When the cam follower falls into the above recess and the follower reaches the bottom of the recess, the transmission ring is moved to a position where the rotation speed of the output shaft is set to 0 to stop the drive system. A control device for performing an operation and a second operation of starting the drive system by pulling out the cam follower from the recess on the cam disk and moving the speed change ring in the speed increasing direction by the start signal. It is characterized by having.

As the above-described frictionless continuously variable transmission, there is one described in Japanese Patent Publication No. 57-13221 developed by the applicant (hereinafter, this is referred to as an R-type transmission).

 A roller is usually used as the cam follower.

The above-described operation performed by the control device is a braking operation, and the characteristic of the R-type transmission that "the magnitude of the torque that can be generated with a decrease in the rotation speed of the output shaft is increased" is used for this braking operation. You. On the other hand, the above-described second operation performed by the control device is a starting operation, and the characteristic of the R-type transmission that "a large torque can be generated when the rotation speed of the output shaft is close to 0" is used for this starting operation.

Operation: When a stop signal is input to the control device during the rotation of the output shaft by the above configuration, the cam follower contacts the peripheral surface of the cam disk while rotating in the recess of the cam disk by the rotation of the cam disk. The cam follower falls. At this time, the cam follower moves the speed change ring to the low speed side, and stops the output shaft at the bottom of the recess.
Next, when a start signal is input while the output shaft is stopped, the cam follower comes out of the recess of the cam disk, and at the same time, the cam follower moves the speed change ring to the high speed side, and the output shaft rotates at high speed. . In this case, since the stop signal and the start signal can be arbitrarily input, continuous rotation can be performed over the recess, and the stop time can be arbitrarily adjusted.

FIG. 1 is a side view showing an example of a start / stop device according to the present invention, FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, and FIG. FIG. 4 is an explanatory view of the operation, and FIG. 4 is an explanatory view of the relationship between the cam disk and the cam follower. Hereinafter, the present invention will be described with reference to these drawings.

In FIG. 1, (1) is an R-type transmission driven by an electric motor, which drives an output shaft (3) via a worm gear device (2) shown in FIG. Mounted on the output shaft (3) is a cam disc (5) provided with four recesses (4) on the circumference. Reference numeral (6) denotes a roller as a cam follower operated by a cam disk (5), which is attached to one arm (8) of a bell crank (7). (9) is the other arm of the bell crank (7).

(10) is a transmission ring of the R-type transmission (1), and (11) is a spring which exerts a force for moving the transmission ring (10) in the speed increasing direction. A state in which the roller (6) is inserted into the recess (4) of the cam disk (5) and the roller (6) is brought into contact with the center (12) of the recess (4) (the state shown in FIG. 1). In, the ring holder (13) is held at a position where the rotation speed of the output shaft (3) is reduced to zero. (14) is the arm (9) of the bell crank (7) and the ring holder (13) to perform this holding.
And a rack and pinion mechanism interposed therebetween.

When the drive system in the state shown in FIG. 1 is started, the fluid cylinder that releases the internal pressure upon the arrival of the signal (15) is driven by the cam disk (5).
When the roller (6) is pulled out from the upper recess (4), the bell crank (7) is turned counterclockwise and applied to the transmission ring (10) via the rack and pinion mechanism (14). The restraint is released, and the rotation of the output shaft (3) is started together with the displacement of the spring (11).

FIG. 4 shows the pulling up of the roller (6) by the fluid cylinder (16) and the subsequent change in drive state. I in this figure indicates the roller (6) when the drive system is stopped.
And II indicates when the roller (6) is pulled up from the recess (4) and the drive system is ready to start operation. Following state II, the output shaft (3) is rotated
When the stop signal arrives in the state III, the fluid cylinder (16) is operated by the arrived signal to cause the roller (6) to contact and follow the peripheral surface (17) of the cam disk (5). This contact following state of the roller (6) continues through the state of V to the state of VI. V is decelerating, VI
Is the same state as the state of I when stopped by deceleration. Strong braking occurs in the V state.

In addition, (18) is an adjustable stop for high-speed restriction of the output shaft (3), (19) is a flow path switching valve, and (20) is a pressure fluid source.

Advantageous Effects of the Invention: The present invention relates to a drive system that repeatedly starts and stops, the ability (starting ability) required to quickly reach the rotation speed of the output shaft to a predetermined value and the element having a large inertia at a predetermined position. And the ability (braking ability) required to stop the vehicle immediately when it reaches the maximum value. A comparison between the conventional case using a variable speed motor as a drive source and the one according to the present invention shows that, for example, a drive system using a variable speed motor of 5 hp according to the present invention has a capacity of 1 according to the above two capabilities. A drive system using a horsepower R-type transmission can be substituted, and the capacity of the drive source is made extremely small by the present invention.

In recent years, the inertia of driven equipment tends to gradually increase, so that the drive system of these equipment must also increase the capacity of a drive source in accordance with the increase in inertia. The present invention enables the drive source to have a relatively small increase in capacity in such a case.

Furthermore, the present invention also acts as a positioning device for determining the arrival transmission of an element such as a driven pallet by the entry position of the cam follower into the recess on the cam disk, and jumps over the determined stop position. It is also possible to stop at any stop position.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of a start-stop device according to the present invention, FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1, and FIG. FIG. 4 is an explanatory view of the relationship between the cam disk and the cam follower.

Claims (1)

(57) [Claims] A speed change range includes a point at which the rotation speed of the output shaft is set to zero, the magnitude of torque that can be generated with a decrease in the rotation speed of the output shaft is increased, and the rotation speed of the output shaft is reduced to zero. A frictionless continuously variable transmission capable of generating a large torque in a close state, a cam disk driven by the frictionless continuously variable transmission and provided with one or a plurality of recesses on its periphery;
A cam follower that follows the peripheral surface of the cam disk, a transmission ring as a shift element of the frictionless continuously variable transmission, and the cam follower interposed between the cam follower and a cam disk according to a stop signal. When the cam follower falls into the above recess and the follower reaches the bottom of the recess, the transmission ring is moved to a position where the rotation speed of the output shaft is set to 0 to stop the drive system. A control device for performing an operation and a second operation of starting the drive system by pulling out the cam follower from the recess on the cam disk and moving the speed change ring in the speed increasing direction by the start signal. A drive system start / stop device, characterized in that: