JPH0672789B2 - Weighing unit of constant quantity supply device such as grease - Google Patents

Description

TECHNICAL FIELD The present invention relates to a metering unit of an apparatus for supplying a constant amount of a highly viscous material such as grease.

[Conventional technology]

For example, mechanical devices that incorporate a gear train, such as the Gabox, inject a small amount of grease for lubrication during the assembly process, but for this purpose, use a highly viscous material such as grease. It is essential to have a weighing unit having a function of accurately weighing even a small amount and discharging the grease after weighing.

Conventionally, as a weighing unit having the above functions,
A plunger type metering / discharging mechanism is used.

[Problems to be Solved by the Invention] However, FIGS. 4 and 5 cited as one of known examples
The weighing unit shown in the figure comprises a weighing plunger M and its driving cylinder D, but has the following problems due to its structure.

That is, in the cylinder 11 of the measuring plunger M, the material suction hole 11a and the discharge hole 11b are formed at different positions along the stroke of the plunger 22, and the drive piston 33a is formed at the rear end of the plunger 22. Is connected, and the stroke amount (discharge amount) adjusting rod is attached to the tip of the cylinder 11.
11c is provided, and further, the plunger 22 has a material reservoir chamber 22a and a material passage 22b communicating with the chamber 22a. Incidentally, 33b is a piston rod of the drive cylinder D, and 33c and 33d are drive air supply / discharge ports.

Thus, when the plunger 22 retreats to the left in the figure by an appropriate stroke amount, the material supplied under pressure enters the cylinder 11 through its suction hole 11a and the tip of the plunger 22 is measured. And stroke adjustment rod
The material is stored in the material storage chamber 22a and the fixed volume chamber 11d sandwiched by 11c.

The material is discharged by advancing the plunger 22 retracted to the tip until the tip comes into contact with the adjusting rod 11c (right side in the figure).
Although the material to be sucked is filled in the fixed amount space of the cylinder 11 sandwiched between the adjusting rod 11c and the tip of the plunger 22, the material reservoir chamber 22a and the passage 22b, the material supplied under pressure is By the time of filling the spaces 11d, 22a, 22b of
There is a time lag.

In addition, even if the discharge is completed, the material reservoir chamber 22a of the plunger 22 is
Since the material remains in the passage 22b and the passage 22b, it is necessary to eject the previous material in order to inhale and eject the material having the same viscosity but different conditions such as viscosity. There is an absurdity and annoyance that so-called blank ejection must be performed until the ejection can be performed from the ejection hole 11b, that is, until the ejection of the residual material is completed.

Furthermore, the grease supplied from the grease pump to the suction hole 11a has a high pressure, and this pressure is received by the plunger 22, so in order to discharge the grease in the cylinder 11, use a large piston for the fixed amount of grease. Another problem is that the grease meter must be pushed by air, which makes the grease meter large in size.

An object of the present invention is to provide a weighing unit that does not have the above-mentioned difficulties.

[Means for Solving the Problems]

The structure of the present invention for solving the above-mentioned problems is mainly formed on a stroke stroke of a cylinder by a metering plunger having a material suction hole and a discharge hole, and a drive cylinder connected to the plunger. In a metering unit of a constant-volume feeding device such as grease, a stopper member that is smaller in diameter than the plunger and has a variable position is attached to the tip of the plunger part that is formed integrally with the piston rod of the drive cylinder. And the slide plunger having an inner diameter shorter than the effective length of the plunger and having an inner diameter loosely inserted into the guide plunger and an outer diameter equal to that of the piston rod are mounted on the guide plunger. Adjusting the sliding amount of the slide plunger with respect to the guide plunger with the stopper member It, is characterized in that so as to suction material, the discharge amount quantitatively.

[Work]

The slide plunger slides on the guide plunger, which is integrated with the piston rod of the drive cylinder, with its sliding amount being variable, so that the amount of grease and other materials supplied under pressure is reduced to a predetermined amount for each stroke of the drive piston. Weigh and discharge the measured material itself.

〔Example〕

Next, an example of the embodiment of the present invention will be described with reference to FIGS.

In FIG. 1 and FIG. 2, M is a material metering / discharging portion of a plunger type, and here, in front of and behind the metering cylinder 1A, cylindrical housing portions 1B, 1C are connected in series. There is. Before and after the stroke of the metering cylinder 1A, a suction hole 1a and a discharge hole 1b for the material to be supplied under pressure are formed.

Reference numeral 2 denotes a plunger that is loosely inserted into the metering cylinder 1A of the plunger M, and its rear end side (left side in the drawing) is integrated with the rod 3b of the piston 3a in the drive cylinder D, while the tip end side (see the drawing). On the right side of) is formed on a guide plunger 2a formed by a rod thinner than the outer diameter of the plunger 2.

This guide plunger 2a has a length sufficiently larger than the entire length of the metering and discharging parts 1A to 1C, and has a screw 2b on the front end side before and after the part protruding from the housing part 1C.

A slide plunger 4 having the same outer diameter as the outer diameter of the plunger 2 is loosely inserted in the guide plunger 2a. The slide plunger 4 is formed so that its entire length is sufficiently shorter than the total internal effective length of the metering cylinder 1A and the housing portion 1C, and the tip side (right side in the figure) serves as a seat for a stopper member 5 described later. It is formed on the thick end portion 4a so as to function.

Thus, the stopper member 5 is formed by a nut-shaped member having a front half portion (left side in the drawing) formed in the tubular portion 5a and a rear half portion provided with a female screw 5b to be screwed into the screw 2b. .

In addition, 5c is a lock nut of the stopper member 5, and 5d is a cylindrical portion 5a.
A spring which is installed inside the cylinder and acts toward the left in the figure so as to push back the thick end 4a of the slide plunger 4, 6a detects the right stroke end of the piston 3a in the drive cylinder D, and therefore the right stroke of the cylinder 3 The limit switch 6b provided at the end of the stroke is a limit switch provided at the housing 1C for detecting the fine movement of the thick end 4a of the slide plunger 4 at the left end of the stroke of the piston 3a.

As described above, each of the members 1 to 6 constitutes an example of the weighing and discharging unit of the present invention.

For example, as shown in FIG. 3, the unit has a suction hole.
1a is connected to a grease can G via a discharge pump P, and a discharge hole 1b is connected to a grease injection gun I having an appropriate structure,
Inject gun I by measuring the required amount of grease in grease can G
The amount of grease concerned is discharged and supplied to. Next, an example of this operation will be described.

Now, the piston 3a of the drive cylinder D is at the end of the left stroke (first
(Fig.), The starting end of the guide plunger 2a in the plunger 2 is aligned with the suction hole 1a, and the slide plunger 4 is on the guide plunger 2a.
Due to the action of the spring 5d, its thick end portion 4a is located near the left end of the stopper member 5. At this time, the thick end
A minute gap is formed between the front surface of 4a (right side in the figure) and the front surface of stopper member 5 (left side in the figure) by the action of the spring 5d.

When the plunger 2 is in the above-mentioned position, the grease pressurized by the pump P is supplied to the suction hole 1a, so that the grease is generated between the rear surface of the plunger 2 and the front surface of the slide plunger 4 in the measuring cylinder 1a. It will be filled in the fixed quantity space 7 formed between them.

When the grease is pressurized and supplied to the space 7 and filled in the space 7, the slide plunger 4 slightly moves to the right against the repulsive force of the spring 5d, and actuates the limit switch 6b. Is electrically detected.

Therefore, for example, when the piston 3a of the drive cylinder D is operated so as to move to the right stroke based on the detection signal, the piston rod 3b, the plunger 2, the guide plunger 2
a, the slide plunger 4, and the stopper member 5 move integrally to the right side of the drawing.

Near this end of the rightward travel stroke, the thick end 4a of the slide plunger 4 comes into contact with the end of the housing portion 1C so that it cannot move to the right. At this time, the left end of the slide plunger 4 is aligned with the position of the discharge hole 1b.

However, even if the slide plunger 4 is stationary, the plunger 2, the guide plunger 2a, and the stopper member 5 are still in the second position.
As it moves to the right as shown in the figure, the fixed volume 7 filled with grease is narrowed as the front end of the plunger 2 moves, so the filled grease is discharged into the discharge hole 1b.
Will be discharged from.

This discharge stroke is performed until the front end surface (the right side surface in the figure) of the plunger 2 contacts the rear end surface (the left side surface in the figure) of the slide plunger 4 as shown in FIGS.

The completion of discharge is detected by detecting that the piston 3a of the drive cylinder D has reached the right stroke end by the limit switch 6a. The stroke of the drive cylinder D is the air supply / exhaust hole 3
This is done by switching and supplying pressurized air from c and 3d.

In this way, a high-viscosity material such as grease, which is pressurized and supplied to the fixed quantity space 7, can be weighed in a fixed amount and discharged and supplied to the outside.

The volume of the fixed volume 7 can be changed by moving the stopper member 5 back and forth on the screw 2b of the guide plunger 2a.

〔The invention's effect〕

The present invention is as described above, and since the plunger has a coaxial composite structure and a fixed amount space is formed on the outer peripheral surface of the plunger, highly viscous materials such as grease to be supplied under pressure do not remain in the measuring unit, Since every measured material is discharged to the outside every time it is measured, it is extremely rational because there is no emptying and no material such as grease remains inside after completion of the work. Further, since the grease pressure is not applied to the piston even if the pressure of the grease supplied from the grease pump is high, the device can be downsized even if the amount of fixed amount of grease increases.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an example of the weighing unit of the present invention when measuring materials, FIG. 2 is a cross-sectional view of the same when discharging, and FIG. 3 is a system diagram of an example of a constant quantity supply device of grease using the weighing unit of the present invention. FIG. 4 is a cross-sectional view of a conventional weighing unit when measuring a material, and FIG. 5 is a cross-sectional view of the same when discharging. 1A: fixed amount cylinder, 1B, 1C: housing, 1a: suction hole, 1b: discharge hole, 2 ... plunger, 2a ... guide plunger, 3 ... drive cylinder, 4 ... slide plunger, 5 ... … Stopper member, 6a, 6b …… Limit switch, 7 …… Quantitative space

Claims (1)

[Claims] 1. A metering device for a constant amount of grease or the like, which is mainly composed of a material intake hole, a metering plunger having a discharge hole, and a drive cylinder connected to the plunger on the stroke of the cylinder. In the unit, at the tip of the plunger portion formed integrally with the piston rod of the drive cylinder, a guide plunger having a diameter smaller than that of the plunger and having a variable position stopper member attached to the tip side is connected and formed. The guide plunger is formed by inserting a slide plunger that is shorter than the effective length of the plunger and has an inner diameter that is loosely inserted into the guide plunger and an outer diameter that is the same as the piston rod. By adjusting the sliding amount with the stopper member, the amount of material suction and discharge Metering unit of dispensing device such as grease, characterized in that so as to quantify.