JPS58118367A - Nonuniform crank motion equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transfer bar for transporting workpieces in machine tools or industrial machines, in which the transfer bar or sliding body is started without impact using constant speed rotation by an electric motor, and is continuously accelerated or decelerated. The present invention relates to an inconstant speed crank motion device that is characterized by being able to stop quietly.

Conventionally, various mechanisms have been considered and used for converting constant speed rotational motion obtained by electric motors etc. into reciprocating motion, but constant speed delivery mechanisms are used when transporting workpieces in machine tools etc. However, there is a problem in that a rapid change in acceleration occurs when starting or stopping, causing vibration or shock to the workpiece, and as the speed of the device itself increases, an inconstant motion mechanism is required. An example of this is a system in which the rotating motion of the binion is directly converted into an acceleration/deceleration feed motion by cranking the binion, but the cranking motion of the binion causes a large swing change in the meshing feed rods. However, it has the disadvantage that it is large in size and stable operation cannot be obtained.

Furthermore, even those that utilize a direct piston crank movement mechanism require a larger structure to obtain the required stroke, and have a drawback in high-speed performance.

In order to deal with the above, patent applications filed by the same applicant as the present invention (Japanese Patent Application No. 55-35961, Japanese Patent Application Laid-Open No. 56-13466)
No. 2) has already been proposed, providing a device that can smoothly start and stop a moving member by combining a crank mechanism that performs non-uniform motion and a planetary gear mechanism. Further improvements were made to realize an inconstant speed crank motion device with improved high-speed performance. Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a longitudinal sectional front view, and FIG. 2 is a view taken in the direction of the ■ arrow in FIG. In FIGS. 1 and 2, l is a drive gear (#), which is fixed to the drive shaft 2. In FIGS. The drive shaft 2 is connected to a reduction gear with a brake motor (not shown), etc., and rotates the drive gear 1.

A driven gear 3 meshes with the drive gear 1 and rotates as a driven gear. A moving member 4 (transfer bar) having a rack 4a is engaged with the upper part of the driven gear 3, and the moving member 4 is supported so as to be movable in the horizontal direction.

A member 5 such as a crank bin is fitted at a position of radius r parallel to the axis of the drive shaft 2, and an engagement member 6 is attached to this. Further, a sliding body 8 is attached to the shaft 7 of the driven gear 3. 9 is a base on which the drive shaft 2 is fitted, and 0110 is a holding member that swings while keeping the positions of the drive gear 1 and the driven gear 3 constant.

Reference numeral 11 denotes a swinging arm in which long grooves 11a and llb are cut. The engagement member 6 is slidably engaged with the long groove 11a, and the shaft g located at the rotation center of the driven gear 3 is slidably engaged with the long groove 11b. Further, a pin 13 is inserted into one upper end of the swinging arm 11 and one upper end of a support member 12 extending from the base 9, and the swinging arm 11 is pivotally supported as a swinging fulcrum. A bracket 14 is attached to the other end of the shaft 7, and a pair of backup rollers 15.15 are provided above the bracket 14 to support the moving member 4. A connecting rod 17 extends from one end of the moving member 4 via a bottle 16.
A movable base is attached to the other end of the connecting rod 17. With the above configuration, the engaging member 6 provided at a position eccentric to the rotation center of the drive gear l and the swinging arm 11 that engages with the engaging member 6 are Due to this action, when the driving gear 1 rotates once at a constant speed, the moving member 4 performs one stroke of inconstant linear motion. The mode of operation will be explained below. Third
The figure is an operation mode diagram showing the movement of the swing arm 11, and FIG. 4 is an explanatory diagram illustrating the operation of the present device.

It is assumed that the shaft 7 of the driven gear starts from a position on the central axis gg. Here, the swing arm 11 is in an upright state with respect to the bin 13. When the drive gear 1 is rotated once in the direction of the arrow at a constant angular velocity that overlaps ω (with the center position being considered), the moving member 4 gradually accelerates according to the rotation angle θ of the engagement member 6 and the speed increases. is increased, and the rotation angle θ of the engaging member 6 is
When reaching −K, the speed of the moving member y 4; tv = v,
Ninaru.

However, after passing θ-2, the moving member 4 is gradually decelerated and stops smoothly at θ-21r (one rotation).The moving member 4 can be moved backward by rotating the drive gear 1 in the reverse direction (one rotation). It returns to its original position following the reverse process of moving forward.

The swing arm 11 starts swinging around point 0 as the rotation angle θ progresses. Here, the swing angle between the central axis gg and the center line of the swing arm 11 is defined as ψ. The rotation of the drive gear 1 at a constant angular velocity always attempts to move the moving member 4 forward in the direction of the arrow through the driven gear 3 at a constant speed V. At the same time, the swinging arm 11 that is moved by the engaging member 6 starts swinging in a direction opposite to the direction in which the moving member 4 moves forward. The shaft 7 of the driven gear 3 is slidably fitted into the long groove 11b above the swing arm 11 via the sliding body 8, so that it rotates planetarily in the same direction as the rotational direction of the drive gear 1. do.

The movement speed of the driven gear 3 toward the center of the shaft 7 due to the rocking motion of the rocking arm 11 and the decrease in relative speed due to the planetary rotation of the driven gear 3 are in the direction of decelerating the forward speed of the moving member 4. to work. Therefore, the moving speed V of the moving member 4 is the composite speed of the moving speed V of the moving member 4 generated by the constant angular velocity and the relative moving speed v3 generated by the swinging arm 11 when the swinging arm 11 swings. Since the swinging direction of 11 changes, it also has the effect of increasing the speed of the moving member 4. That is, between the rotation angle θ゛-0 and π/2, V
It starts smoothly from r-Q and gradually accelerates.

In addition, between θ-- and π, the swinging direction of the swinging arm 11 changes to the same direction as the forward direction and the eating speed increases, and when it reaches 0-π,
The speed of the moving member 4 becomes maximum.

Next, between θ-π and 3/2π, the speed is gradually decelerated in a state opposite to the case of speed increase, and between θ-372t and 2, the swing arm 11
The oscillation direction changes to the opposite direction from the forward direction! The speed of the @ member 4 is further reduced, and it stops smoothly when the drive gear 1 rotates once and reaches θ-2π.

As described above, by the swinging action of the swinging arm 11, the horizontal movement speed V of the movable member 4 is made into an inconstant motion, and an ideal transfer speed change is obtained.

A theoretical analysis of the above operation is as follows.

(1) When calculating the eccentricity of the engaging member for zero start, that is, if the eccentricity of the eccentric engaging member 6 provided on the driven gear 3 is r, the swinging angle ψ of the swinging arm 11 is However, χ=r/a The angular velocity uJ of the four-moving arm 11, is the moving speed v3 of the driven gear 3 (at 0-K) y, t== (t) 1111 R-, * uJ, R
f311-2 mermaid θ + λ The conditions for the moving member 4 to start at 0 are y' -2v, -.

Assuming θ-0, lJI is the pitch diameter of the drive gear 1. Therefore, (2) When calculating the speed of the moving member, the composite speed V of the moving member 4 is V=vH+v! °゛I6 However, v4 is the horizontal component of the center movement speed of the driven gear 3, and the relative circumferential speed of the driven gear 3, v! , the angular velocity of the holding member 10 is 0
is J chant + n-' (a/b ・sin (1) -'f
win-'(a/bs+1nuttt)-LL)o
t...(7) The rotation speed NIO of the holding member 10 is N, or= 39 uJ, , , 4 (Y'zov)
-(91 Relative rotational speed N of driven gear 3 is (, Z, , Z, G; tmlil, relative number of teeth of 3, relative rotation j!
V! =π・D,・N.

However, L) ■ is the pitch diameter of the follower gear 3, so (3) When calculating the displacement of the moving member, the displacement S of the moving member is the radius r, v, s by applying the actual values to each formula above.
can be determined. Figure 5A is an embodiment of the operating characteristic diagram of the inconstant speed crank interlocking according to the present invention.As shown in the v-I diagram in Figure 5A, the moving member 4 starts smoothly and causes sudden speed changes. It is clear that the engine stops smoothly without any friction. ■ in the same figure shows the horizontal displacement S and θ of the moving member 4.
It shows the relationship between

Further, FIG. 5(2) shows a curve of the acceleration a' of the moving member 4 and the time t. ^ In the same figure, β is a diagram showing cycle + - J id curve motion, and in the case of 2, the maximum value of velocity 3 acceleration is larger than that of uniform acceleration motion and zigzag motion, so it is suitable for high speeds and light loads. . On the other hand, the diagram (2) according to the present invention shows that the maximum velocity part of the cycloid curve motion has a constant velocity σ)i
;i: minute is inserted, and the speed and acceleration are generally lower than the cycloid curve motion, and the position of the highest acceleration is also outside the cycloid curve motion, so it is a speed curve suitable for transporting heavy objects. is obtained.

According to the present invention, the entire structure of the transfer device is compact and simple, which has the advantage of requiring less space and being able to be manufactured at low cost. Furthermore, since the swinging change of the moving member 4 is small, it can be ignored.

Since the speed change when the moving member 4 starts and stops is small and operations can be performed smoothly, there is also the advantage that the positioning accuracy of the moving table can be improved, and it can be applied to various mechanical transfer devices.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal cross-sectional front view thereof, FIG. 2 is a view taken in the direction of arrow II in FIG. 1, and FIG. 3 is an operation diagram showing the movement of the swing arm. , FIG. 4 is an explanatory diagram illustrating the operation of this device, and FIG. - Driven gear, 4... Moving member 6... Engaging member 8... Sliding body 7... Shaft "... Shaft body 9... Base 1
0... Holding member 11... Swinging arm lla, l
lb...Long groove 12...Supporting member 13...Bin
14...Bracket 15...Backup roller
-6...Bin 17...Connecting rod Patent applicant Hitachi Seiki Co., Ltd. J 3 Figure 3 1a Figure 4

Claims (1)

[Claims] a base 9 and a drive shaft 2 rotatably provided on the base 9;
A drive gear 1 connected to the drive shaft 2, an engagement member 6 provided eccentrically with respect to the rotation center of the drive gear 1, a driven gear 3 that meshes with the drive gear 1 and follows the drive gear 1, and the drive gear 1 and the driven gear. 3
a holding member 10 for holding the position of the moving member 10; a moving member 4 that is transmitted and driven by the engaging member 6 and the moving gear 3 to move in a linear direction; and a moving member 4 extending from the base 9 to above the moving member 4. An inconstant velocity crank motion device characterized in that a support member 12 and an upper end of the swinging arm 11 are pivotally connected to the upper end of the support member 12 using the upper end of the swing arm 11 as a swing fulcrum.