JP2517475Y2 - Excavator sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an excavator that excavates and propels under high-pressure ground, such as in tunnel construction, and maintains the sealability between the rotary cutter and the machine casing. Regarding the device.

[Prior Art] Conventionally, as a sealing device of this type, for example, the actual opening 63
-56793 publication. This sealing device has a rotary cutter attached to the front end of the excavator body,
This rotary cutter is rotated to move forward while excavating.
A plurality of annular seal members having the same shape are mounted in parallel at equal intervals in an annular gap provided between the casing of the machine body and the outer periphery of the rotary cutter. Between these seal members is a pressure chamber to which the lubricant is supplied in proportion to the muddy water pressure. The lubricant is gradually reduced in pressure and supplied from the front pressure chamber facing the excavation surface toward the rear inner pressure chamber. The lubricant in the front pressure chamber in the muddy state is on the high pressure side. By discharging the lubricant supplied to each pressure chamber to the outside, it is a structure that prevents the intrusion of muddy water into the inside of the body casing and secures a required sealing property.

[Problems to be Solved by the Invention] By the way, in the case of the sealing device disclosed in this publication, the lubricant is gradually reduced in pressure from the pressure chamber on the front side facing the excavation surface toward the pressure chamber on the rear side and supplied. Because of the structure, it has the following problems. That is, when the front seal member facing the cutting surface and subjected to high-pressure muddy water is damaged or destroyed due to deterioration in durability, the differential pressure between the rear seal member and the rear seal member becomes large. The load acting on the seal member is increased and the service life is shortened, and the service life is reduced proportionally to the rear third stage and the fourth stage.

An object of the present invention is to provide a sealing device for an excavator that solves the above problems and has an improved durable life.

[Means for Solving the Problems] A sealing device for an excavator according to the present invention is provided between a casing of a machine body and an outer peripheral surface of a rotary cutter, and has a plurality of sealing members facing from the front side to the rear side. A plurality of sealing members are provided in which pressure lubricant for sealing is supplied to the pressure chambers arranged and arranged between the respective sealing members while gradually reducing the pressure from the front side facing the excavation surface to the rear side. A seal group of several stages is formed by several groups, and an intermediate pressure chamber is provided between one seal group and the other seal group, and the intermediate pressure chamber and the discharge device are connected by a drain pipe. In addition, a drain switching valve is provided in the drain pipe to switch the discharge switching valve for muddy water and lubricant that have entered the intermediate pressure chamber between the second stage sealing group and the second stage sealing group due to the functional deterioration of the first stage sealing group facing the excavation surface. Discharge device through drain pipe by operation When the amount of muddy water and the lubricant to be discharged reaches a predetermined amount or pressure, the supply of the lubricant to the first stage seal group is stopped and switched to the supply to the second stage seal group. Has been done.

[Operation] Due to the deterioration of the function of the high pressure side first seal group facing the excavation surface, the muddy water and the lubricant supplied to the first stage seal group enter the intermediate pressure chamber between the second stage seal group. . The infiltrated muddy water and the lubricant are discharged from the discharge device through the drain pipe by the switching operation of the discharge switching valve. When the discharged muddy water and lubricant reach a specified amount or pressure,
The supply of the lubricant to the first stage seal group is stopped based on the signal from the detection means that detects this. At the same time, the drain pipe is shut off by the switching operation of the discharge switching valve, and the lubricant is supplied to the second stage seal group. Thereafter, similar switching is performed to the subsequent third stage seal group and thereafter.

[Embodiment] An embodiment of a sealing device for an excavator according to the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic view of a part of the front side of the excavator. That is,
A rotary cutter 11 is rotatably supported inside the body casing 10, and rotary excavation is performed with the head portion 11a of the rotary cutter 11 facing the face excavation surface (left side in the drawing). Between the outer peripheral surfaces of the head portion 11a and the boss portion 11b of the rotary cutter 11 and the body casing 10, a plurality of annular seal members 20, 21, 22-is interposed at equal intervals in the axial direction.

FIG. 2 is an enlarged cross-sectional view in which a plurality of seal members 20, 21 to are arranged. In the case of this embodiment, nine seal members are provided.
The embodiment in which 20 to 28 are arranged is shown. Nine sealing members 20 to 28 are arranged from the left side to the right side of the drawing, that is, from the left side of the drawing facing the face for excavating the face to the right side of the drawing inside the body casing 10. These seal members 20-
28 are three groups each, so that the first group of sealing members 20 to 22 facing the excavation surface are the first stage seal group A, and the second group of sealing members 23 to 25 are the second stage. The seal group B and the seal members 26 to 28 of the third group are the third stage seal group C.

However, in the embodiment, the structure in which the first to third stage seal groups A to C are arranged in parallel is shown, but on the front side of the first stage seal group A, that is, on the side facing the face excavation surface. It is possible and more preferable to arrange other sealing mechanisms such as a labyrinth sealing mechanism.

Further, in the gap 30 between the machine casing 10 and the outer peripheral surface of the rotary cutter 11, the gaps between adjacent ones of the seal members 20 to 28 are pressure chambers 31, 32 and 33. Supply pipes 41, 42, 43-for supplying pressurized grease (lubricant) as a sealing material are introduced into these pressure chambers 31-.
Pressurized grease is supplied through each supply pipe 41 to the supply tanks 51, 52,
It is pumped from 53 to by a pressure pump. Switching valves 61, 62, 63 are provided in each supply pipe 41-.

Here, in the intermediate pressure chamber 34 between the first-stage seal group A and the second-stage seal group B, the supply pipe 44 leading to one supply tank 51 is introduced, and the supply pipe 44 is discharged. Switching valve 64
Is provided. That is, one switching valve 61 and the intermediate pressure chamber
A discharge switching valve 64 for discharge control is further provided between the discharge control valve 34 and the control valve 34. Further, the discharge switching valve 64 is connected to the discharge device 80 communicating with the outside of the machine body through the drain pipe 70. By the switching operation of the discharge switching valve 64, the pressurized grease in the pressure chamber 34 can be discharged to the outside of the machine body through the drain pipe. Further, the drain pipe 70 is equipped with a detecting means 81 by a flow meter or a pressure gauge. The signal detected by the detecting means 81 is sent to a control device (not shown), and the signal controlled here is sent as an actuation signal toward each of the switching valves 61 to 64 and the discharge switching valve 64. Is.

Next, an operation mode and an action of the sealing device of the embodiment having the above configuration will be described.

The head portion 11a of the rotary cutter 11 is made to face the face excavation surface, and the rotary cutter 11 is rotationally driven to start excavation. Initially, the pressurized grease for sealing the muddy water generated in this excavation work is supplied only to the first stage seal group A. That is, in response to an operation command from the control device, each switching valve 61
Is a supply tank 51 to a supply pipe 41 to a first stage seal group A.
It can be switched so as to communicate with each pressure chamber 31 to 33 through 43. By supplying pressurized grease to each pressure chamber 31-33,
Airframe casing 10 and rotary cutter 11 by the step seal group A
The required sealability is secured in the gap 30 with the outer peripheral surface of the. When it is determined that the durability life of the first-stage seal group A has decreased due to long-term excavation work, switching control is performed to use the second-stage seal group B this time. During this time, if any or all of the three seal members 20 to 22 composing the first stage seal group A are broken or damaged due to their service life and their functions deteriorate, the pressure chambers 31 to 33 are supplied with pressure. The pressure grease flows out and enters the pressure chamber 34 between it and the second stage seal group B.

At this time, the discharge switching valve 64 operates to connect the drain pipe 70 to the intermediate pressure chamber 34. Due to this communication, the pressurized grease that has entered the pressure chamber 34 passes through the drain pipe 70 and is discharged from the discharge device 80 to the outside. When the discharge pressure reaches a predetermined value by the detection means 81, this is detected and a signal is sent to the control device, and a switching signal from the control device is sent to each of the switching valves 61 to. At the same time, the drain switching valve 64 is switched to change the drain pipe 70.
To the pressure chamber 34, and the supply pipe 44
To communicate. Further, the pressurizing grease, which has been supplied to the pressure chambers 31 to 33 in the first stage seal group A until the respective switching valves 61 to have been switched and operated, is now changed to the pressure chamber 35 in the second stage seal group B. , 36 (including the pressure chamber 34 between the first stage seal group A)
Supply through the supply pipes 44 to 46.

Based on the above procedure, when the life of the second stage seal group B is shortened, switching to the next third stage seal group C is performed. During use of the first-stage seal group A, the respective seal members 23 to 25 of the second-stage seal group B are rotationally operated in a non-loaded state, so that the lifespan of them is only slightly reduced.

By switching and using from the first-stage seal group A to the third-stage seal group C, the durability as seen from the overall sealing performance is the same as that of the present embodiment. About 1.5 times more than if they were just equally spaced
It was confirmed that the improvement was several to several times.

[Effects of the Invention] As described above, in the sealing device for an excavator according to the present invention, a plurality of sealing members are arranged in groups of several stages,
Since the structure is such that the pressurized grease (lubricant) for sealing is supplied in order from the first group, the high-pressure side sealing member deteriorates its function due to the life as in the conventional structure in which the same number of sealing members are arranged at equal intervals. By doing so, the problem that the subsequent rear sealing members are burdened is solved, and the durability seen from the overall sealing property is significantly improved.

[Brief description of drawings]

FIG. 1 is a schematic side sectional view of a front part of an excavator to which a sealing device according to an embodiment of the present invention is applied, and FIG. 2 is a piping layout diagram of the sealing device according to the embodiment. [Explanation of symbols] 10 …… Machine casing 11 …… Rotating cutter 20 ～ …… Tooth profile 31 ～ …… Pressure chamber 41〜 …… Supply pipe 51〜 …… Supply tank for pressurized grease (lubricant) 61〜 …… Switching valve 64 …… Discharging switching valve 70 …… Drain pipe 80 …… Discharging device 81 …… Flow meter and other detection means A …… First stage seal group B …… Second stage seal group C …… Third stage seal group

Claims (1)

(57) [Scope of utility model registration request] 1. A pressure chamber, which is interposed between a body casing and an outer peripheral surface of a rotary cutter, in which a plurality of seal members are arranged from a front side to a rear side facing an excavation surface and which is provided between the seal members. In a seal device in which a pressurized lubricant for sealing is gradually reduced in pressure from the front side facing the excavation surface to the rear side, a plurality of seal members are formed into several stages of seal groups. , An intermediate pressure chamber is provided between the one seal group and the other seal group, the intermediate pressure chamber and the discharge device are connected by a drain pipe, and the drain pipe is provided with a discharge switching valve to face the excavation surface. The muddy water and the lubricant that have entered the intermediate pressure chamber between the second-stage seal group due to the functional deterioration of the first-stage seal group are discharged from the discharge device through the drain pipe by the switching operation of the discharge switching valve, and the discharged muddy water is also discharged. And lubrication A seal for an excavator, characterized in that, when the amount of the agent reaches a predetermined amount or a predetermined pressure, the supply of the lubricant to the first-stage seal group is stopped and switched to the supply to the second-stage seal group. apparatus.