JP3352486B2 - Molding machine positioning device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning device for a molding machine, and more particularly to an improvement thereof.

[0002]

2. Description of the Related Art In various molding machines such as an injection molding machine and a die casting machine, the approach and separation (mold opening and closing) between a fixed plate provided with a fixed mold and a movable plate provided with a movable mold, injection, A positioning device is provided to read the operating position of a molded product or the like. As this positioning device,
For example, in an injection molding machine that opens and closes a mold by moving a movable plate toward and away from a fixed plate by a drive cylinder and a toggle mechanism,
A toggle mechanism is connected to the tip of a cylinder rod that penetrates the fixing plate, a rack support member is fixed to this connection portion, and a rack is mounted on the rack support member, and a pinion that meshes with the rack is rotatable on the fixing plate. There is a type in which a rotary potentiometer is linked to a rotating shaft of the pinion.

[0003] When the rack and the pinion are used in combination as described above, the backlash always exists in the meshing state of the rack and the pinion, and the position detection shifts in both the approach and separation directions. There is a problem. Further, in the position detecting device having the above configuration, the rack is firmly supported at and near the mounting portion of the rack support member, so that the meshing with the pinion is reliable, but the meshing state becomes worse as the distance from the mounting portion increases. However, the backlash also becomes large, so that an accurate position cannot be read and the accuracy is extremely poor. Further, the adjustment for reducing the backlash requires a lot of man-hours such as disassembly and assembly, which is complicated and causes a great loss of time.

By the way, since the backlash is originally an essential structure for smoothly engaging the rack and the pinion and rotating the pinion without hindrance, it is unavoidable not to provide the backlash. Then
Backlash occurs in the opposite direction, which also constitutes a limit of positioning accuracy.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a positioning device comprising a rack and a pinion, which is configured to always maintain a constant meshing state regardless of backlash.

[0006]

Thus, according to the invention of claim 1 of the present application, "a fixed plate (2b) provided with a fixed die (1b) and a die of the fixed plate (2b)" A moving plate (4b) provided with a moving mold (3b) on the side facing the surface; and a driving means (5B) for driving the moving plate (4b) toward and away from the fixed plate (2b).
A fixing member (7b) for fixing the driving means (5B), a rack (2) and a rack supporting member (4) attached to the driving means (5B), and the above-mentioned so as to mesh with the rack (2). Fixing member (7b)
The pinion (3) is rotatably mounted on a rocking member (5), one end of which is rotatably supported by the fixing member (7b). The other end of the rocking member is elastically urged against a fixed member so that the pinion (3) presses the rack (2) and a component force is generated in the axial direction of the rack, and the rotation shaft of the pinion (3) is rotated. And a positioning device (1) for a molding machine, which is linked to a rotary potentiometer (8).

[0007] The molding machine provided with the positioning device (1) of the present invention comprises a fixed plate (2b) provided with a fixed mold (1b) and a movable mold.
Any one having a moving plate (4b) provided with (3b) and a driving means (5B) for moving the moving plate (4b) close to and away from the fixed plate (2b) can be used. For example, driving means
A preferable example of (5B) includes the drive cylinder (6b) and the toggle mechanism (5b), but is not limited thereto.

[0008] In the positioning device (1) of the present invention, the rack support member (4) for supporting the rack (2) is provided in the driving means (5B). When a toggle mechanism (5b) is employed for the driving means (5B), it is preferable that the drive mechanism (5B) is attached to the toggle mechanism (5b).

The pinion (3) meshing with the rack (2) is provided on a fixed member (7b), and is attached at this time via a swing member (5). That is, the rotation shaft of the pinion (3) is attached to one end of the swing member (5), and the swing member
(5) The other end is attached to the fixing member (7b) with a swing shaft. Further, the swing member (5) is elastically urged by a rack supporting member (4) by an elastic locking member such as a spring (6). This elastic bias is performed such that a component force can be generated in either the approach direction or the separation direction.

[0010] A rotary potentiometer (8) is linked to the rotary shaft of the pinion (3).

[0011]

According to the present invention, the pinion (3) is elastically urged against the rack support member (4), and is always moved in that direction by a component force generated in either the approach direction or the separation direction. As the rack (2) moves in the approaching direction or in the separating direction, each tooth of the pinion (3) will The teeth are brought into contact with each other only in contact with the surfaces in the same direction, so that there is no play due to backlash between the approach direction and the separation direction.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments, but the present invention is not limited thereto. Embodiment 1 FIG. 1 is a schematic side view of an injection molding machine provided with a positioning device according to claim 1 of the present application, FIG. 2 is a schematic rear view of a main part of FIG. 1 illustrating a pinion mounting structure, and FIG. FIG. 4 is a schematic cross-sectional view taken along line AA of FIG. 3.
In these figures, the injection molding machine (A) is composed of a mold part (B), an injection part (C), and a positioning device (1). The mold part (B) was provided with a fixed plate (2b) provided with a fixed mold (1b), and a movable mold (3b) provided on a side of the fixed plate (2b) facing the mold surface. A moving plate (4b), a toggle mechanism (5b) for driving the moving plate (4b) toward and away from the fixed plate (2b), and a drive cylinder
(6b) and a tail end (7b) for fixing the toggle mechanism (5b) and the drive cylinder (6b).
The injection unit (C) is an injection cylinder (1c) that kneads, heats, and melts the resin
And a screw (2c), and an injection drive section (3c) for driving the screw (2c) for injection.

As shown in FIGS. 2 to 4, the positioning device (1) includes a rack support member (4) supported and fixed to a cylinder rod connecting portion (5b ₁ ) of a toggle mechanism (5b), and a rack support member (4). A rack (2) fixed to the lower surface, a pinion (3) meshing with the rack (2), a swing member (5) supporting the pinion (3), and a swing member (5) and a tail It comprises a spring (6) locked between the end (7b) and a rotary potentiometer (8).

The swinging member (5) has a tail part which is pivotally supported by a pin (53) on a main body part (51) provided with a through hole (5h) and a protruding piece (7b ₁ ) of a tail end (7b). (52). In the through hole (5h), a pinion (3) is rotatably mounted by a shaft (31) from one side, and a rotary potentiometer (8) is inserted from the other, and the shaft (31) and the potentiometer (8) are inserted.
Are connected by a coupling (9) in the through hole (5h).

The spring (6) is locked between the other end of the swinging member (5) and the tail end side locking portion (7b ₂ ) located diagonally upward in FIG. As shown by the arrow in
The tension F due to (6) is decomposed and the pinion (3) presses the rack (2) by the component of the vertical component (Fa), and the pinion (3) is moved by the component of the horizontal component (Fb). A pressing force is applied on the shaft in the separating direction (the direction shown in the figure). The tension F of the spring (6) is set so that the component force Fb is higher than the rack moving speed at the time of the separating operation.

The operation of the positioning device (1) of the injection molding machine (A) configured as described above will be described. At the time of the proximity operation, the cylinder rod (5b ₁ ) of the drive cylinder (6b) is pushed out, whereby the toggle mechanism (5b)
Is moved in the approaching direction (← direction in FIG. 2), and the rack (2) also moves in the same direction. At this time, as shown in FIG. 5, since the pinion (3) is urged in the direction of FIG. 5 by the component force Fb, the tail end side wall (31) of each tooth of the pinion (3) is always in the rack (2). ) Mold side wall of each tooth (2
You will proceed in contact with 1). During the separating operation, the cylinder rod (5b ₁ ) of the drive cylinder (6b) is returned to the cylinder, whereby the cylinder rod connecting portion of the toggle mechanism (5b) is moved in the separating direction (see FIG. 2).
Direction), and the rack (2) also moves in the same direction. At this time, as shown in FIG. 6, the component force Fb applied to the pinion (3)
And the moving direction of the rack are the same, but the component force Fb
Is faster than the moving speed of the rack, so the tail end side wall of each tooth of the pinion (3) is always
(31) comes into contact with the mold side wall (21) of each tooth of the rack (2) and proceeds.

Therefore, no backlash occurs between the approach operation and the separation operation, and the moving distance of the rack in any direction is directly converted into the rotation speed of the pinion (3), and this is converted into the rotation type potentiometer (8). ), The position can be detected with high accuracy.

[0018]

According to the present invention, since the pinion is pressed against the rack and is also pressed in a fixed direction along the pinion galax axis, the engagement between the rack and the pinion can be made in both the approaching and separating operations. Since there is no deviation and no backlash occurs, the rack movement distance in any direction can be accurately changed to the rotation speed of the pinion, and accurate and highly accurate position detection can always be performed.

[Brief description of the drawings]

FIG. 1 is a schematic side view of an injection molding machine provided with an example of a positioning device according to claim 1 of the present application.

FIG. 2 is a schematic rear view of a main part of FIG. 1, illustrating a pinion mounting structure.

FIG. 3 is an enlarged schematic view of a main part of FIG. 2;

FIG. 4 is a schematic cross-sectional view taken along line AA of FIG. 3;

FIG. 5 is an explanatory view of a main part configuration for explaining a meshing state between a rack and a pinion at the time of proximity operation.

FIG. 6 is an explanatory view of a main part configuration for explaining a meshing state of a rack and a pinion during a separating operation.

[Explanation of symbols]

(2) Rack (3) Pinion (4) Rack support member (5) Swing member (6) Spring (8) Rotary potentiometer (9) Coupling (2b) Fixing plate (4b )… Movable plate (5b)… Toggle mechanism (6b)… Drive cylinder (7b)… Tail end

Claims (1)

(57) [Claims] A fixed plate provided with a fixed mold,
A movable plate provided with a movable mold on a side of the fixed plate facing the mold surface, a driving unit that drives the movable plate toward and away from the fixed plate, and a fixing member that fixes the driving unit. A rack and a rack support member attached to the driving means,
A pinion provided on the fixed member so as to mesh with the rack, wherein the pinion is rotatably mounted on a swinging member having one end pivotally supported by the fixed member so that the pinion is rotatable. And the other end of the rocking member is elastically urged against a fixed member so as to generate a component force in the axial direction of the rack, and the rotation shaft of the pinion is linked to a rotary potentiometer. Positioning device.