JP2559131Y2 - Bucket type drilling rig - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bucket type excavator mounted on a bucket of an excavator such as a hydraulic excavator.

[0002]

2. Description of the Related Art A hydraulic excavator 1 shown in FIG. 5 is used for excavating a ground or a pavement at a construction work site or the like. A bucket 6 is assembled via an arm 5 to the tip of a boom 4 that swings from the upper swing body 3. The boom 4 swings up and down by driving a hydraulic boom cylinder 4a, and the arm 5 pin-coupled to the tip of the boom 4 also swings up and down by driving the hydraulic arm cylinder 5a. The bucket 6 is connected to the arm 5 by the connecting pin 7.
The tip of a rod 8 rotatably attached to the tip and extending from a bucket cylinder 6 a with the head side connected to the arm 5 is connected to a bracket 6 b by a connecting pin 9. For this reason, the bucket 6 swings back and forth according to the expansion and contraction of the rod 8, and excavates the ground with the cutting edge at the tip.

[0003] The above-mentioned hydraulic excavator 1 is used for excavating hard ground such as earthen rocks, soft rocks or gravels, or for ripping work on a pavement road. When the drilling cannot be performed as expected, the bucket 6 at the tip of the arm 5 is replaced with a hydraulic breaker (not shown) suitable for crushing the hard ground, and excavation is performed by the shock or vibration generated by the hydraulic breaker. Methods are being taken to increase efficiency.

[0004] However, although the hydraulic breaker is suitable for crushing hard ground, it is completely unsuitable for loading work of shaved rocks and earth and sand into a transport vehicle or the like. The breaker had to be replaced with the original bucket 6. Also,
Even when the soil quality of the ground is rich in hard and soft changes, the hydraulic breaker and the bucket 6 must be frequently replaced each time the soil quality changes, and it takes time to exchange the excavator at the tip of the arm 5. However, the efficiency of excavation work was inevitably reduced.

On the other hand, in order to cope with such a problem, there has been proposed a hydraulic shovel of a type in which a hydraulic breaker is assembled to a bucket and integrated, and the hydraulic breaker is operated as required. However, for example, Japanese Utility Model Laid-Open No. 1-138949
The hydraulic excavator disclosed in No. "bucket type excavator" has a configuration in which a bucket and a hydraulic breaker are selectively used according to the properties of the ground, and since the bucket and the hydraulic breaker cannot be used at the same time, digging while crushing is performed. I couldn't do that. On the other hand, there is also a configuration in which a bucket automatically operates according to the properties of the ground. For example, Japanese Patent Laid-Open No. 61-257541, "breaker-mounted bucket"
The bucket type excavator 11 shown in FIG. 6 disclosed in US Pat.
And a cutting tooth 14 projecting forward from a cutting edge of the bucket 12 is connected and fixed to a striking piston 15 of a breaker body 13 via an elastic body 16. The bucket type excavator 11 has a devised hydraulic circuit. The excavator 13 operates the breaker body 13 when excavating a ground having a large excavation resistance, and operates the breaker 13 when the crushed soil and the like are loaded by the bucket 12. The circuit configuration is such that the main body does not operate.

[0006]

The conventional hydraulic bucket type excavator 11 can automatically operate the hydraulic breaker 13 according to the ground. However, such as a ripping operation for excavating a pavement road, etc. In the work of excavating while excavating teeth 14 by pressing the excavating teeth 14 against the road to exert an impact force on the ground, a large load acts on the breaker body 13 when the striking piston 15 drives the excavating teeth. When the striking piston 15 is pushed back by the reaction, a strong force acts on the breaker body 13. If the reaction force from the ground is received properly by the breaker body 13, the breaker body 13
In order to accelerate the deterioration of the breaker body 13, the breaker body 13 is buffered and supported by the elastic body 16 provided behind the breaker body 13, so that direct adverse effects are not exerted on the breaker body 13. However, since the breaker body 13 is shaken by the buffering support of the elastic body 16, the striking force applied from the breaker body 13 to the striking piston 15 is not effectively transmitted to the excavating teeth 14, and the crushing ability is not exhibited for the number of struck. There were issues such as.

The sliding contact surface between the receiving metal 18 and the striking piston 15 is designed so as to be cut off from the outside by a cylindrical metal receiving member 19 for guiding and holding the excavating teeth 14. Because the seal between 19 and the digging tooth 14 is not perfect,
There has been a problem that earth and sand generated by excavation intrude into the sliding contact surface between the receiver 18 and the striking piston 15 from between the receiver 19 and the excavating teeth 14, and the wear of the receivers 18 and 19 tends to progress.

It is an object of the present invention to receive a reaction force acting on a hydraulic breaker substantially by a bucket, not to apply an unnecessary load to the breaker body, to extend the life of the breaker body, and to improve the excavation efficiency. The goal is to improve

[0009]

SUMMARY OF THE INVENTION According to the present invention, a chisel is reciprocally inserted into and held at a tip of a bucket by a predetermined distance, a cutting tooth attached to the tip of the chisel, and a striking piston driven by fluid pressure. A breaker body for hitting the chisel, and a breaker body fitted at the chisel insertion holding portion of the bucket to slide and guide the chisel, and provided at the tip so as not to apply a reaction force from the chisel to the breaker body. The flange portion includes a wear bush that defines a return limit position of the chisel, and is provided between the tip portion of the bucket and the chisel so as to extend and retract so as to surround a reciprocating displacement space of the chisel. A bucket type excavator which achieves the above object by providing a seal for blocking a sliding contact surface between a chisel and the wear bush from the outside world. A.

Still further, in the bucket type excavator according to the present invention, an end groove of the chisel is extended into the breaker body, and a pin locked in the breaker body is formed in the end part. By defining the chisel, the chisel is prevented from rotating and the forward limit position is defined.

[0011]

According to the above construction, the wear bush defines the limit position of the return of the chisel, prevents the reaction force from the ground directly against the breaker body, and the striking force applied to the striking piston from the breaker body. Is efficiently transmitted to the excavated teeth, and high crushing ability can be exhibited with a small number of hits.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a driving apparatus for a bucket type excavator according to the present invention will be described below with reference to FIGS. FIG. 1 is a side view showing an embodiment of a hydraulic excavator to which the bucket type excavator of the present invention is applied, FIG. 2 is a longitudinal sectional view of a bucket portion of the hydraulic excavator shown in FIG. 1, and FIG.
FIG. 4 is a plan view of a bucket portion of the hydraulic shovel shown in FIG. 1, and FIG. 4 is a longitudinal sectional view of a hydraulic breaker portion of the hydraulic shovel shown in FIG.

In a hydraulic excavator 21 shown in FIG. 1, a hydraulic breaker for driving a digging tooth 22 by hydraulic pressure is incorporated in a bucket 24. As shown in FIG. 3, the excavating tooth 22 is composed of a main tooth 22a and sub tooth 22b arranged on both sides thereof. Since the sub tooth 22b is a fixed tooth, only the main tooth 22a is driven by the hydraulic breaker 23. As shown in FIGS. 2 and 3, the bucket 24 has a pin hole 25 for the connecting pin 7 connected to the tip of the arm 5 and a pin hole 26 for the connecting pin 9 connecting the tip of the rod 8 to the bracket 27. Has been drilled. A cutting edge 28a serving as a cutting blade is formed at the tip of the back plate 28 integrated with the bracket 27, and the sub tooth 22b is fixed to the vicinity of the side plate 29 of the cutting edge 28a. The main tooth 22a located at the center of the left and right sub tooth 22b is a chisel 30
Is connected to a tip of the base by a connecting pin 31.

As shown in FIG. 4, the chisel 30 is composed of a rod-like member having a sharp tip and a large-diameter portion 30a and a medium-diameter portion 3
Ob and the small-diameter portion 30c are reduced in three stages in order, and are held by the back plate 28 and the protection plate 32 covering the center of the upper surface thereof in a reciprocating manner only in a predetermined section. That is, the opening at the end formed between the back plate 28 and the protection plate 32 is closed by the bush with a hole 33.
The middle diameter portion 30b of the chisel 30 is slidably fitted in the wear bush 34 fitted in 3. The small diameter portion 30b of the chisel 30 extends into the breaker main body 23a, and is driven to hit by the breaker main body 23a. The breaker body 23a receives the hydraulic oil supplied from a hydraulic circuit (not shown) provided outside the bucket 24 via a hose at two positions 3
Supply / discharge control is performed by the port switching valve 35, and the chisel 30 is driven back and forth by hydraulic pressure. In the embodiment, the main tooth 22, the chisel 30, the breaker body 23a, the two-position three-port switching valve 35, and the like constitute the hydraulic breaker 23.

The breaker body 23a has two large-diameter portions 3
A spool-type impact piston 36 having 6a and 36b and a small diameter portion 30c of the chisel 30 are slidably fitted in a cylinder 37 for a predetermined section. 36, a piston high pressure chamber 37b, a pilot chamber 3
7c, an oil discharge chamber 37d, a piston reversal chamber 37e, and a gas chamber 37f for buffering the striking piston 36 are defined. The piston high-pressure chamber 37b is a space for applying a high pressure to the front large-diameter portion 36a of the striking piston 36.
It is communicatively connected to the small-diameter pressure receiving portion 35 a of the port switching valve 35, and receives the supply of hydraulic oil from the oil supply pipe 38. The pilot chamber 37c is a space for detecting the displacement of the striking piston 36 as internal hydraulic oil pressure, and is connected to the large-diameter pressure receiving portion 35b of the 2-position 3-port switching valve 35. The oil discharge chamber 37d forms a space for discharging the hydraulic oil between the large diameter portions 36a and 36b in front and rear of the striking piston 36 to the hydraulic circuit side, and is connected to the oil discharge pipe 39 in communication. . The piston reversing chamber 37e has a function of receiving the supply of hydraulic oil from the two-position three-port switching valve 35 and reversing the striking piston 36 from the backward movement to the forward movement. Gas chamber 3
At 7f, the distal end of the impact piston 36 extends,
The striking piston 36 is buffered by compressing the gas filled therein and increasing the pressure.

When hydraulic oil is fed into the high-pressure piston chamber 37b in a state where the two-position three-port switching valve 35 communicates the piston reversing chamber 37e and the oil drain pipe 39 as shown in FIG. At the same time, the piston high-pressure chamber 37b communicates with the pilot chamber 37c with the return movement of the impact piston 36. The hydraulic oil in the pilot chamber 37c is supplied to the large-diameter pressure receiving portion 35b of the 2-position 3-port switching valve 35.
However, since the pressure receiving area of the large-diameter pressure receiving portion 35b is larger than the pressure receiving area of the small-diameter pressure receiving portion 35a, the two-position three-port switching valve 35 switches from the illustrated state, and the piston reversing chamber 37e is connected to the oil supply pipe. It communicates with the road 38. As a result, the hydraulic oil from the oil supply line 38 is guided into the piston reversing chamber 37e, and the striking piston 36 is reversed from the backward stroke to the forward stroke. At this time, since the gas pressure in the gas chamber 37f acts on the striking piston 36, the striking piston 36 receives an extremely large driving force and moves forward. When the striking piston 36 moves close to the forward movement limit, the tip of the striking piston 36 strikes the chisel 30, and the main tooth 22a moves forward in a shocking manner. At this time, since the pilot chamber 37c communicates with the oil discharge chamber 37d, the pressure of the hydraulic oil in the large-diameter pressure receiving portion 35b decreases, and the hydraulic oil from the oil supply pipe 38 supplied to the small-diameter pressure receiving portion 35a is reduced. Due to the pressure, the two-position three-port switching valve 35 returns to the illustrated state.

The chisel 30 struck by the striking piston 36 is slidably held at the middle diameter portion 30b by the wear bush 34 and slidably at the small diameter portion 30c by the cylinder 37. The impact of the piston 36 can always be transmitted to the main tooth 22a on the same axis. Further, as will be described later, since the excavation reaction force does not directly act on the cylinder 37 of the breaker body 23a, and the cylinder 37 does not swing back and forth, left and right,
The impact force transmitted from the striking piston 36 to the chisel 30 is also converted into the excavating force with extremely high efficiency.

Here, an engaging groove 40 is formed over the peripheral surface of the small diameter portion 30c of the chisel 30 extending into the cylinder 37 over a predetermined distance range, and the chisel sliding surface of the cylinder 37 is formed. Pin 4 that is rotatably locked in a locking groove 41 formed in
2 are engaged with this engagement groove 40. For this reason, the chisel 30 is moved from the pin 42 engaged with the engagement groove 40 to the cylinder 3.
7 and at the same time, the forward limit and the backward limit defining the reciprocating distance of the chisel 30 are defined when the rear end of the engaging groove 40 abuts on the pin 42. Is done. However, the return limit is determined by the wear bush 34 locking the chisel 30 immediately before the front end of the engagement groove 40 abuts the pin 42.

That is, the wear bush 34 fitted to the chisel insertion holding portion of the bucket 24 is composed of a cylindrical bush body 34a for slidingly guiding the chisel 30, and a flange integrally formed in a flange shape at the tip of the bush body 34a. Part 34
b, the large diameter portion 30a and the medium diameter portion 30b of the chisel 30
A gap δ ₁ formed between a locking surface formed by a step portion between the pin and the front surface of the flange 34 b is formed between the pin 42 and the engagement groove 40.
It is designed to be smaller in than the gap [delta] ₂ is formed. For this reason, the load when the main tooth 22 a receives the excavation reaction force is received by the flange portion 34 b that defines the return limit position of the chisel 30.

The tip of the bucket 24 and the chisel 3
A retractable seal 43 surrounding the reciprocating displacement space of the chisel 30 is disposed between the seals 43. This seal 43
Has a front end fixed to the large diameter portion 30a of the chisel 30 and a rear end fixed to the side surface of the flange portion 34b of the wear bush 34 and the front end side surface of the bush 33. Can expand and contract. Therefore, the sliding surface between the chisel 30 and the wear bush 34 is always shut off from the outside by the seal 43 that expands and contracts in the axial direction in accordance with the movement of the chisel 30. Wear bush 34
No foreign matter such as earth and sand or aggression enters between the chisel 30 and the chisel 30, and unnecessary wear of the wear bush 34 can be reliably suppressed.

However, the wear bush 3 which has reached the wear limit
4 can be easily removed from the bush 33 after the seal 43 is removed and the chisel 30 is pulled out, and can be replaced with a new one prepared as a fixture.

As described above, in the bucket type excavator 44 in which the hydraulic breaker 23 is integrated with the bucket 24, the wear bush 34 is fitted to the chisel insertion holding portion of the bucket 24, and the chisel 30 is slid and guided, and the wear is reduced. Since the return limit position of the chisel 30 is defined by the flange portion 34b provided at the tip of the bush 34, it is not necessary to operate the breaker body 23a because the ground is relatively soft. When the main tooth 22a is fixed at the return limit position,
Alternatively, the breaker body 23 may be used for ripping work.
a, the flange 34b of the wear bush 34 locks the chisel 30 instead of the pin 42 in the breaker body 23a even when the striking piston 36 is pushed back to the limit position of the return movement by the reaction of the main tooth 22a immediately after the driving. Therefore, the excavation reaction force from the ground does not directly act on the breaker main body 23a, so that the breaker main body 23a is not damaged by an excessive force. In addition, since the chisel 30 itself is always slidably guided in the axial direction by the wear bush 34, when the main tooth 22a is continuously driven, the striking force given from the breaker body 23a to the striking piston 36 can be efficiently applied to the main tooth 22a. Therefore, a high crushing ability can be exhibited with a small number of hits.

The bucket type excavator 44 has a telescopic seal 43 surrounding the reciprocating displacement space of the chisel 30 between the tip of the bucket 24 and the chisel 30.
Since the sliding surface between the chisel 30 and the wear bush 34 is configured to be shielded from the outside world, earth and sand generated by excavation do not enter the sliding surface between the chisel 30 and the wear bush 34. The sliding surface is not stained by the foreign matter.

Furthermore, the bucket type excavator 44
The distal end of the chisel 30 is extended into the breaker main body 23a, and the pin 42 locked in the breaker main body 23a is engaged with the engaging groove 40 formed at the distal end to prevent the chisel 30 from rotating. It is possible to define a movement limit position.

The above bucket type excavator 44
The present invention can be applied to all construction machines other than the hydraulic excavator 21, such as a wheel loader and a dozer excavator, which use a bucket 24 in which a hydraulic breaker 23 is integrated.

[0026]

[Effects of the Invention] As described above, according to the present invention,
Since the return limit position of the chisel is specified by the wear bush, there is no direct reaction force from the ground to the breaker body, and the striking force given to the striking piston from the breaker body is efficiently used. Since it can be transmitted to the excavated teeth, high crushing ability can be exhibited with a small number of hits.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of a hydraulic excavator to which a bucket type excavator of the present invention is applied.

FIG. 2 is a longitudinal sectional view of a bucket portion of the excavator shown in FIG.

FIG. 3 is a plan view of a bucket portion of the excavator illustrated in FIG. 1;

4 is a vertical sectional view of a hydraulic breaker portion of the excavator shown in FIG.

FIG. 5 is a side view showing an example of a conventional hydraulic excavator.

FIG. 6 is a longitudinal sectional view showing an example of a conventional bucket type excavator.

[Explanation of symbols]

 22a Main tooth 23 Hydraulic breaker 23a Breaker body 24 Bucket 30 Chisel 34 Wear bush 36 Striking piston 43 Seal 33 Bucket type excavator

Claims (2)

(57) [Scope of request for utility model registration] 1. A chisel inserted and held at a tip end portion of a bucket so as to be reciprocally movable by a predetermined distance, a cutting tooth attached to the tip end portion of the chisel, and a striking piston driven by fluid pressure to strike the chisel. A breaker body and a flange portion fitted at the chisel insertion holding portion of the bucket to slide and guide the chisel, and a flange portion provided at a tip end so as to prevent a reaction force from the chisel from acting on the breaker body, are provided with a rear end of the chisel. A wear bush that defines a movement limit position,
A seal is provided between the tip portion of the bucket and the chisel so as to extend and retract so as to surround a reciprocating displacement space of the chisel, and to seal a sliding contact surface between the chisel and the wear bush from the outside. A bucket type excavator characterized by the above-mentioned. 2. The chisel has a distal end extending into the breaker body, and a pin locked in the breaker body engages an engaging groove formed in the distal end, The bucket-type excavator according to claim 1, wherein a rotation stop and a forward limit position are defined.