JPH1054345A - Device for preventing viscous fluid infiltration into main hydraulic cylinder of viscous fliud pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent infiltration into a main hydraulic cylinder of wet viscous fluid from a force feed piston. SOLUTION: In a gland part 14 of main hydraulic cylinders 5a, 5b, a plurality of packings 19,20 are newly provided. Between the packings 19, 20, a recessed groove is provided over the total periphery, so as to make operating oil flow. A supply side flow path 22 supplying operating oil to the recessed groove and a discharge side flow path 23 discharging the operating oil are provided in a radial direction in the gland part 14. A supply side flow path 27 made to communicate with the supply side flow path 22 is provided in a frame 26. A discharge side flow path 28 made to communicate with the discharge side flow path 23 is provided in the frame 26, When pressurized operating oil is supplied to a recessed groove 21 through the supply side flow paths 21, 22, a viscous fluid stuck to piston rods 8a, 8b is floated by the operating oil, discharged through the discharge side flow paths 23, 28 and captured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a viscous fluid pump used for preventing a viscous fluid sucked and discharged by a double-row piston type viscous fluid pump from entering a main hydraulic cylinder from a gland of the main hydraulic cylinder. The present invention relates to a device for preventing a viscous fluid from entering a main hydraulic cylinder.

[0002]

2. Description of the Related Art One example of a viscous fluid pump for sucking and discharging a viscous fluid such as concrete, in which a suction and discharge valve is a swing valve type, is shown in FIGS. 1a, two suction outlets 2
a, 2b are arranged side by side in the left-right direction, and two transport cylinders 3a, 3b each having a front end attached to the front wall 1a of the hopper 1 so as to communicate with the two suction / discharge ports 2a, 2b are arranged in parallel. In addition, two main hydraulic cylinders 5 a, 5 b are provided on the rear end sides of the two transport cylinders 3 a, 3 b via a cleaning chamber 4.
b, and hydraulic pistons 7a and 7b housed in the two main hydraulic cylinders 5a and 5b, and hydraulic pistons 6a and 6b housed in the two transport cylinders 3a and 3b.
And piston rods 8a and 8 each penetrating the cleaning chamber 4.
b, the hydraulic pistons 7a and 7b of the main hydraulic cylinders 5a and 5b are alternately advanced and retracted, so that the pressure-feeding pistons 6 in the transport cylinders 3a and 3b are
a and 6b are simultaneously moved forward and backward. On the other hand, in the hopper 1, an oscillating tube 9 bent in an S-shape is arranged, and the front end side oscillates in the left-right direction, and the
The swinging pipe 9 is configured to alternately communicate with the two suction and discharge ports 2a and 2b. The swinging of the swinging pipe 9 is performed by swinging a connecting shaft 10 having one end fixed to the swinging pipe 9 and protruding forward of the hopper 1. Moving lever 1
After the viscous fluid 13 in the hopper 1 is sucked into the two transport cylinders 3a or 3b, the piston 6a or 6b for pressure feed is rotated. , The viscous fluid 13 in the transport cylinder 3 a or 3 b is discharged through the swing pipe 9.

In the double-row piston type viscous fluid pump as described above, the pressure-feeding pistons 6a and 6b are
When sliding on the inner surfaces of the pistons a and 3b, the viscous fluid may leak to the rear surfaces of the pistons for pressure feeding 6a and 6b and become paste-like and adhere to the piston rods 8a and 8b.

On the other hand, the main hydraulic cylinders 5a, 5
The gland part 14 of the piston rod penetration part on the b side is
As shown in FIG.
5, 16; a packing 17; and a bearing (bush) 18. The structure is a combination of the cleaning chamber 4 and the main hydraulic cylinders 5a and 5b.

[0005]

However, even if a plurality of dust seals 15 and 16 are attached to the gland portion 14, the particles such as mortar in the viscous fluid are very fine, and if they adhere to the piston rods 8a and 8b, the dust seals may be removed. 1
5, 16 and the main hydraulic cylinder 5
a and 5b. If the amount of the viscous fluid that enters the main hydraulic cylinders 5a and 5b increases, the entered viscous fluid may reach the oil pump and the hydraulic equipment together with the hydraulic oil and damage them. There was a problem that had to be done in the eyes.

Accordingly, the present invention is intended to prevent a viscous fluid from entering a main hydraulic cylinder from a gland of a main hydraulic cylinder connected to a cleaning chamber.

[0007]

According to the present invention, in order to solve the above-mentioned problems, a hydraulic piston in two main hydraulic cylinders and a piston for pressure feeding in two transport cylinders are each provided with one piston rod. The piston is alternately advanced and retracted to discharge the viscous fluid sucked into the transport cylinder, and a plurality of pistons are provided on the ground portion of the main hydraulic cylinder through which the piston rod passes. In the viscous fluid pump provided with the dust seal described above, a plurality of packings are provided in the gland portion, and a groove is provided at a position between the plurality of packings so as to be continuous along the entire circumference, and communicates with the groove. The supply-side flow path and the discharge-side flow path of the hydraulic oil to be provided are provided in the gland portion in the radial direction, and the flow path communicating with the supply-side flow path and the flow path communicating with the discharge-side flow path are formed by the hydraulic pressure of the main hydraulic cylinder. A configuration in which the hydraulic fluid of the hydraulic circuit is connected to a single hydraulic circuit provided separately from the channel, supplied to the concave groove from the supply-side channel, and then discharged and circulated from the discharge-side channel. And

When the viscous fluid adheres to the piston rod after leaking from the pressure-feeding piston, a part of the fluid comes into the inside of the gland portion, but the working oil of the single hydraulic circuit is supplied to the groove provided in the gland portion. The viscous fluid adhering to the piston rod can be captured by floating with hydraulic oil and discharging through a flow path on the discharge side. This prevents the viscous fluid from entering the main hydraulic cylinder through the gland.

[0009] Hydraulic circuits are provided by providing a flow path for communicating with a supply side flow path and a discharge side flow path provided in the ground portion on a frame outside the ground portion and connecting to a hydraulic circuit. Circuit piping can be performed easily.

Further, by providing a flow path for communicating with the flow path on the supply side provided in the ground portion on the side wall of the cleaning chamber, the formation of the flow path becomes easy.

Further, if the single hydraulic circuit is constituted by a supply line for supplying hydraulic oil to the gland from the oil pump and a line for returning hydraulic oil discharged from the gland to the oil tank through a filter, The viscous fluid captured by the hydraulic oil discharged from the gland can be filtered by the filter.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show an embodiment of the present invention. As shown in FIG. 5, two transport cylinders 3a and 3b and two main hydraulic Cylinders 5a, 5b are provided, and pistons 6a, 6b for pressure feeding in transport cylinders 3a, 3b and main hydraulic cylinders 5a, 5b are provided.
Hydraulic pistons 7a and 7b in 5b are connected by two piston rods 8a and 8b penetrating the washing chamber 4, and the piston rods 8a and 8b are located on the main hydraulic cylinders 5a and 5b side of the washing chamber 4. A plurality of (two in the figure) dust seals 15 and 16, a packing 17 and a bearing 18 are provided on the gland portion 14 of the main hydraulic cylinder, which penetrates, from the cleaning chamber 4 side.
In the configuration in which the packing 19 is provided between the dust seals 15 and 16 in the gland portion 14 and the packing 20 is also provided between the dust seal 16 and the packing 17,
0, the packing structure of the gland part 14 is changed so that a passage for flowing the hydraulic oil can be secured, and a concave groove 21 is provided on the inner circumferential surface at the position between the packings 19 and 20 over the entire circumference. A supply-side flow path 22 and a discharge-side flow path 23 communicating with the concave groove 21 are provided so as to penetrate in the radial direction, respectively.
The outer ends of the flow paths 22 and 23 are closed by lids 24 and 25.

The cleaning chamber 4 and the main hydraulic cylinders 5a, 5b
At the front ends of the two frames 26 interposed therebetween, a hydraulic oil supply-side flow path 27 is formed to communicate with the supply-side flow path 22 of the ground section 14. A hydraulic oil discharge-side flow path 28 is formed to communicate with the flow path 22 in the middle of the flow path 22 and to communicate with the discharge-side flow path 23 of the gland part 14, and is connected to the discharge-side flow path 23 of the gland part. An independent hydraulic circuit 29 is connected to each hydraulic oil supply side flow path 27 and each hydraulic oil discharge side flow path 28 provided in the two frames 26, and the hydraulic oil in the oil tank 30 is supplied to the supply side flow path. The oil tank 30 from the path 27 passes through the flow path 22, the concave groove 21, the flow path 23, and the discharge-side flow path 28 of the ground portion 14.
Return to and circulate.

As shown in FIG. 2, the exclusive hydraulic circuit 29 supplies the hydraulic oil discharged from the oil tank 30 by the oil pump 31 to the supply side flow path 2 of one frame 26 through a line 32.
7 and discharged from the discharge-side flow path 23, the liquid is introduced into the supply-side flow path 27 of the other frame 26 and discharged from the discharge-side flow paths 23 and 28.
The hydraulic oil discharged from the tank is returned to the oil tank 30 via the line 33 and the filter 34. 35 is a joint for connecting the lines 32 and 33 to the filter 34.

The viscous fluid in the transport cylinders 3a and 3b is
When the viscous fluid leaks from the pressure-feeding pistons 6a, 6b and adheres to the outer periphery of the piston rods 8a, 8b when the pressure-feeding pistons 6a, 6b perform suction and discharge by advancing and retreating, the piston rods 8a, 8b move forward and backward. From the cleaning chamber 4 to the ground 1 of the main hydraulic cylinders 5a, 5b.
4 and may mix with the oil in the main hydraulic cylinders 5a and 5b.

In the present invention, the packings 19 and 20 are provided in the gland portion 14 to change the packing structure of the gland portion 14, and the flow paths 22 and 23 and the groove 21 are provided. Piston rods 8a, 8b
After it acts on the outer circumference of the frame 26, a passage for discharging the oil from the discharge-side flow path 23 is ensured. When guided from the passage 27 to the concave groove 21 through the supply-side flow path 22 of the gland portion 14, the piston rods 8 a, 8 b
The viscous fluid adhering to the air is floated and captured, and the flow path 23 on the discharge side from the groove 21 and the discharge side flow path 2 of the frame 26 are further removed.
8 can be sent. Thus, it is possible to prevent the viscous fluid from entering the main hydraulic cylinders 5a and 5b.

When the viscous fluid attached to the piston rods 8a, 8b is discharged into the line 33 through the flow paths 23, 28 by the hydraulic oil, the hydraulic oil containing the captured viscous fluid passes through the filter 34. By this, the viscous fluid is filtered, and the working oil containing no viscous fluid is returned to the oil tank 30 for circulating use.

In the above, according to the present invention, the ground portion 1
The circuit of the hydraulic oil acting on the main hydraulic cylinders 5a,
5b is independent from the hydraulic circuit of FIG.
It does not lead to the oil pumps and hydraulic devices of a and 5b, and does not shorten the life of these devices.

The present invention is not limited to the above embodiment. For example, FIG. 1 shows a case in which the supply-side flow path 27 constituting the hydraulic circuit 29 is provided in the frame 26. Alternatively, the side wall 4a of the cleaning chamber 4
May be provided in the up and down direction so as to communicate with the flow path 22 of the ground portion 14. Also, as shown by a two-dot chain line, the oil pump 31 is connected to the hydraulic circuit 29 shown in FIG.
Between the discharge side of the oil tank and the return side of the oil tank 30
7 may be interposed to be released when the pressure of the hydraulic oil acting on the gland portion 14 becomes abnormally high. Of course, various changes may be made without departing from the scope of the present invention. It is.

[0021]

As described above, according to the present invention, a plurality of packings are provided in the ground portion of the main hydraulic cylinder of a viscous fluid pump in a line with a plurality of dust seals, and a concave groove is provided at an intermediate position on the inner surface. A supply-side flow path and a discharge-side flow path for hydraulic oil that are provided over the entire circumference and communicate with the concave groove are provided in the radial direction, and a flow path that communicates with the supply-side flow path and a flow path that communicates with the discharge-side flow path Is connected to a separate hydraulic circuit separate from the hydraulic circuit of the main hydraulic cylinder, and the hydraulic oil of the single hydraulic circuit is supplied to the concave groove so that the viscous fluid attached to the piston rod is floated and captured. With this configuration, it is possible to prevent the viscous fluid adhering to the piston rod from entering the main hydraulic cylinder from the gland of the main hydraulic cylinder, thereby contaminating the hydraulic oil in the hydraulic circuit of the main hydraulic cylinder. The hydraulic oil replacement cycle can be lengthened, and the hydraulic oil that catches the viscous fluid attached to the piston rod is circulated through a single hydraulic circuit. At the same time, there is an excellent effect that viscous fluid does not flow into the oil pump or the hydraulic device of the main hydraulic cylinder, so that early damage of these devices can be prevented and the life can be extended.

Further, if the flow path for communicating with the supply-side flow path and the discharge-side flow path provided in the gland portion is provided in the frame outside the gland portion, piping of the hydraulic circuit can be easily performed. If the flow path communicating with the flow path on the supply side of the ground portion is provided on the side wall of the cleaning chamber, the flow path can be provided linearly, and the flow path can be formed easily. Further, by providing a filter in the hydraulic circuit, an excellent effect that the captured viscous fluid can be filtered can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a diagram showing a single hydraulic circuit used in the present invention.

FIG. 3 is a partially cut-away side view showing an example of a viscous fluid pump.

FIG. 4 is a view taken in the direction of arrows IV-IV in FIG. 3;

FIG. 5 is an enlarged sectional view showing a gland of a main hydraulic cylinder of a conventional viscous fluid pump.

[Explanation of symbols]

 3a, 3b Transport cylinder 4 Cleaning chamber 4a Side wall 5a, 5b Main hydraulic cylinder 6a, 6b Piston for pressure feed 8a, 8b Piston rod 14 Ground part 15, 16 Dust seal 17 Packing 18 Bearing 19, 20 Packing 21 Depressed groove 22 Supply side flow path 23 discharge side flow path 26 frame 27 supply side flow path 28 discharge side flow path 29 hydraulic circuit 30 oil tank 31 oil pump 32, 33 line 34 filter 36 flow path

Claims (4)

[Claims] 1. A hydraulic piston in two main hydraulic cylinders and a pumping piston in two transport cylinders are respectively connected by one piston rod, and the pumping pistons are alternately advanced and retracted. In a viscous fluid pump in which a viscous fluid sucked into a transport cylinder is discharged, and a plurality of dust seals are applied to a gland portion of a main hydraulic cylinder through which the piston rod passes, A plurality of packings, a groove is provided at a position between the plurality of packings so as to be continuous over the entire circumference, and the supply-side flow path and the discharge-side flow path of the hydraulic oil communicating with the groove are grounded. And a flow path communicating with the supply-side flow path and a flow path communicating with the discharge-side flow path are connected to a single hydraulic circuit provided separately from the hydraulic circuit of the main hydraulic cylinder. circuit After supplying the working oil to the concave groove from the supply-side flow path, the hydraulic oil is discharged from the discharge-side flow path and circulated to the main hydraulic cylinder of the viscous fluid pump. Viscous fluid intrusion prevention device. And a flow path communicating with a flow path on the supply side of the hydraulic oil provided on the ground section and a flow path communicating with a flow path on the discharge side of the hydraulic oil provided on a frame outside the ground section. ,
2. A device for preventing viscous fluid from entering a main hydraulic cylinder of a viscous fluid pump according to claim 1, which is connected to a hydraulic circuit. 3. A flow path provided on the side wall of the cleaning chamber for communicating with a hydraulic oil supply side flow path provided on the ground portion and connected to a hydraulic circuit, and a hydraulic oil discharge side flow path provided on the cleaning chamber side. 2. The viscous fluid intrusion prevention device according to claim 1, wherein the passage is provided on a frame outside the ground portion and connected to a hydraulic circuit. 4. A single hydraulic circuit comprising: a supply line for discharging hydraulic oil in an oil tank by an oil pump and supplying the hydraulic oil to a gland of a main hydraulic cylinder; and a hydraulic oil discharged from the gland through a filter. 4. A structure comprising a return line for returning to an oil tank.
A device for preventing intrusion of a viscous fluid into a main hydraulic cylinder of the viscous fluid pump according to the above.