JPS61289957A - Device for checking generation of mold clamping force in toggle type injection molding machine - Google Patents

Abstract

PURPOSE:To permit sure checking by disposing a pad member to the proper point of a tie bar and detecting the elongating movement of the tie bar with a detector via an expanding lever of which the top end is pressed to the pad member. CONSTITUTION:The pad member 9 is fixed to the proper point of the guid tie bar 3 of a moving die plate of an injection molding machine which clamps molds by a toggle mechanism. A stationary bracket 10 is disposed to the outside of the member 9. The top end of the lever 13 is freely turnably and pivotally fitted to the bracket 10 and the top end of the lever 13 is pressed to the member 9; at the same time, the bottom end is successively connected to a detector 11 such s limit switch.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for detecting the elongation of tie bars in a toggle type injection molding machine to confirm the generation of mold clamping force.

(Prior art and its problems) In the mold clamping mechanism of a toggle injection molding machine, in order to close the mold with a predetermined clamping force, the guide tie bars of the movable die plate must be applied with a clamping force equivalent to the predetermined clamping force. It generates elongation and uses its elastic recovery force to obtain mold clamping force.

The amount of elongation of the quiver is extremely small compared to the length of the tie bar, and conventionally, the amount of elongation can be detected using a third
This is done by the means shown in the figure.

That is, the tie bar ta+ has a long hole (
b), insert the rod (C) into this elongated hole (a), keep the tip of the rod (C) in constant contact with the bottom of the hole due to the elastic force of the spring (dl), and is brought into contact with a digital indicator or dial indicator tel attached to the end face of the tie bar tal, and the amount of extension of the tie bar +111 is detected by the indicator tel.

However, with such a device, only the end face of the tie bar (a) can be used as the location for the detection part, and there is a difficulty in machining to make a long hole fb) in the length direction from the center of the end face of the tie bar. Moreover, it requires highly accurate and expensive measuring equipment such as a digital indicator or dial indicator, and a separate unit must be used to convert it into an electrical signal, resulting in high costs.

(Object of the Invention) The present invention has been made in view of the above-mentioned problems, and provides a toggle type injection molding machine that can easily and accurately detect the elongation of the tie bar by disposing it at any position where the tie bar elongates and moves. The present invention provides a mold clamping force generation confirmation device.

(Structure of the Invention) In order to achieve the above object, the mold clamping force generation confirmation device for a toggle type injection molding machine of the present invention is provided in an injection molding machine that performs mold clamping by a toggle mechanism. A stop member is fixed to the stop member, and a fixing bracket is disposed outside the stop member, and the upper part of the lever is rotatably pivoted to the fixing bracket, so that the upper end of the lever can come into contact with the stop member. It is characterized by having the tie bars facing each other and having their lower ends connected to a detector such as a limit switch.The actual elongation of the tie bar is expanded by a lever to the amount required to operate the detector such as a limit switch, and the mold The structure is such that it can be confirmed as an electrical signal that the mold is closed and mold clamping force is generated.

(Description of Embodiments) An embodiment of the present invention will be described with reference to the drawings. (1) is a link housing, and the four sides of the outer circumference of the link housing and the four sides of the outer circumference of the fixed die plate (2) are connected by tie bars (3). A movable die plate (4) is movably disposed between the link housing (1) and the fixed die plate (2) using tie bars (3) as guides. As is well known, the movable die plate (4) is connected to a mold clamping cylinder (5).
)' is moved via a toggle mechanism (6) that expands and contracts, and the molds (71+81) fixed to die play (21) (41) are clamped.

(9) is a stopper member that is fixed in place on any tie bar (3) outside the moving range of the movable die plate (4), and in the figure it is made by attaching a split ring to the outer circumferential surface of the tie bar, but other A projecting piece-like member may be attached.

00) is a fixed bracket placed outside the backing member (9) fixed to the tie bar (3), and is attached to a suitable position on the machine frame.A detector 11 such as a limit switch is mounted on this bracket 00). It is installed.

Reference numeral 12 denotes a lever whose upper part is rotatably attached to the upper end of the side wall of the bracket 00) by a pin 13, and the lever 12 is attached to the upper end of the lever so that the contact 14 is directed toward the abutting member (9).
9), and a pressing piece 15 fixed to the lower end thereof is brought into contact with the detector 11.

Reference numeral 16 denotes a spring that is press-fitted between the lower center of the lever 12 and the bracket QO), and the pressing piece 15 is constantly connected to the detector 1.
It is pressed against 1.

With the above configuration, we now have the mold clamping cylinder (5).
When the toggle mechanism (6) is activated to extend the mold, and the tie bar (3) is extended and moved by Δl, the upper end contact 14 of the lever 12 in contact with the contact member (9) The lever 12 moves by the same amount in the same direction.
performs circular arc rotation using the pin 13 as a fulcrum.

Since the lever 12 has a longer length B between the pin 13 and the contact piece 15 than the length A between the pin 13 and the contact piece 14,
The actual elongation amount Δl of the tie bar (3) is magnified by B/A times and transmitted to the actuator of the detector 11 via the push contact piece 15, and this amount of expansion is used for the operation of the mold cavity compression process, etc. This is the required minimum amount, and the generation of the mold clamping force can be confirmed as an electrical signal from the detector 11.

Note that the spring 16 moves the lever 1 when the mold clamping force is released.
2 to its original position.

(Effects of the Invention) As described above, according to the mold clamping force generation confirmation device for a toggle type injection molding machine of the present invention, a contact member is disposed at an appropriate position of the tie bar, and the upper end is brought into contact with the tie bar. Since the structure is such that the extension and movement of the tie bar is detected by a detector via a lever, the structure is extremely simple and eliminates the problem of having to install it in a limited space as with conventional devices. It can be easily arranged by using the space of the tie bar, and since the amount of extension and movement of the tie bar is magnified via a lever and transmitted to the detector, it can be confirmed reliably. It is.

Therefore, in the operation of the injection molding machine, such as the compression process of the mold cavity, it is necessary to confirm that mold clamping land has occurred before starting the process, and in the mold clamping process, such as safety interlocks, etc. This is very effective when performing a desired process after confirming that no force is being generated.

Note that even when the device of the present invention is used for the purpose of measuring the amount of movement of the tie bar, a digital indicator or dial indicator can be attached in place of the limit switch to obtain even more accurate measured values.

[Brief explanation of the drawing]

Fig. 1 is a simplified side view showing an embodiment of the present invention, Fig. 2 is an enlarged side view of a mold clamping force generation confirmation device, and Fig. 3 is a longitudinal sectional side view of a conventional tie bar elongation confirmation measuring device. . (3)...Tie bar, (9)...Attaching member, α0・
...fixing bracket, 11...detector, 12...lever, 13...pin.

Claims (1)

[Claims] In an injection molding machine that performs mold clamping using a toggle mechanism, an abutment member is fixed to a suitable position on a guide tie bar of a movable die plate, and a fixing bracket is disposed outside of this abutment member, and the upper end of the lever is rotated to the fixing bracket. A mold clamping force generation confirmation device for a toggle type injection molding machine, characterized in that the lever is pivotally mounted so as to be freely movable, the upper end of the lever is in contact with the abutment member, and the lower end is connected to a detector such as a limit switch.