JP2004162852A - Hydraulic drive crusher - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the load at stopping that acts on the power transmission system transmitting the revolution power of a hydraulic motor on a crush part. <P>SOLUTION: It makes that the lower brake pressure than the maximum drive pressure acts during stoppage by providing a brake valve 19 in a motor circuit 14 and making the setting pressure of a break side relief valve 16 lower than that of a drive side relief valve 15 in this brake valve 19. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hydraulically driven crusher that is driven to rotate by a hydraulic motor to perform a crushing operation.
[0002]
[Prior art]
The conventional technology will be described by taking a mobile crusher as an example.
[0003]
As shown in FIG. 9, the mobile crusher includes a crusher main body 2 such as a jaw crusher, a feeder 3 for supplying a raw material such as a concrete mass to the main body 2 on a traveling body 1 such as a crawler type, and a crusher. An unloading conveyer 4 for unloading articles is mounted, and is operated using an engine (not shown) as a power source.
[0004]
FIG. 10 shows a configuration of a drive system of the crusher main body 2. A hydraulic motor 5 is driven by a hydraulic pump (not shown) using an engine as a drive source, and the rotational force of the motor 5 drives the drive pulley 6 and the transmission belt 7. The crushing action is transmitted to the flywheel 8 of the crushing portion via the eccentric portion, and the jaw (weight) 9 eccentrically attached to the flywheel 8 rotates.
[0005]
Conventionally, in the crusher of this configuration, a brake valve (counter balance valve) as a hydraulic brake means is provided in a motor circuit connecting the hydraulic motor 5 and the hydraulic pump, and when the operation is stopped, the brake valve of the motor circuit is operated by the brake valve. (For example, see Patent Document 1).
[0006]
[Patent Document 1]
JP-A-9-206686 [0007]
[Problems to be solved by the invention]
However, according to this conventional configuration, at the time of stoppage, a brake pressure equivalent to the motor maximum pressure required for driving the motor is applied, so that an excessive load is applied to the belt transmission mechanism.
[0008]
For this reason, a severe slip occurs between the power transmission belt 7 and the drive pulley 6 and the flywheel 8, so that the power transmission belt 7 is easily worn, and a loud slip noise (so-called brake squeal) is generated. .
[0009]
In order to reduce the slip, it is conceivable to increase the tension of the transmission belt 7. However, the belt load becomes larger and the wear becomes more severe, and the load capacity of the drive pulley 6 and the bearing portion of the flywheel 8 is increased. It is not advisable to do so because the adverse effects are large.
[0010]
Further, even if the transmission mechanism is replaced with another type (for example, a chain type), there is no change in that the overload acts on the transmission mechanism at the time of stop and a trouble occurs in the transmission mechanism.
[0011]
Accordingly, the present invention provides a hydraulically driven crusher capable of reducing a load at the time of stoppage acting on a transmission mechanism for transmitting the rotational force of a hydraulic motor to a crushing unit.
[0012]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a hydraulic system having a hydraulic brake means for transmitting a rotational force of a hydraulic motor to a crushing unit by a transmission mechanism to perform a crushing operation and generating a brake pressure on a braking side of the hydraulic motor when stopped. In the driven crusher, the brake pressure by the hydraulic brake means is set to a value lower than the maximum drive pressure of the motor.
[0013]
According to a second aspect of the present invention, in the configuration of the first aspect, the brake pressure is set to a value higher than the driving pressure at the time of steady rotation of the hydraulic motor.
[0014]
According to a third aspect of the present invention, in the configuration of the first or second aspect, a motor circuit that connects a hydraulic motor and a hydraulic pump as a hydraulic source of the motor as a hydraulic brake means includes: A brake valve including a relief valve and a relief valve on the braking side is provided, and the set pressure of the brake side relief valve in the brake valve is set to a value lower than the set pressure of the drive side relief valve. is there.
[0015]
According to a fourth aspect of the present invention, in the configuration of the third aspect, a two-stage relief valve whose set pressure can be switched between a high level and a low level is used as each of the two relief valves, and the braking side is operated according to the forward / reverse rotation of the hydraulic motor. A relief valve control means for controlling both relief valves is provided so that the set pressure of the relief valve becomes lower than the set pressure of the drive side relief valve.
[0016]
According to a fifth aspect of the present invention, in the configuration of the first or second aspect, a control circuit for controlling rotation of the hydraulic motor and a hydraulic brake means are provided in a motor circuit connecting the hydraulic motor and a hydraulic pump as a hydraulic source of the motor. The control valve spool opening characteristic is set so that when the control valve is operated to the stop position, the brake pressure acting on the hydraulic motor is lower than the maximum driving pressure of the motor. It is a thing.
[0017]
According to a sixth aspect of the present invention, in the configuration of the fifth aspect, the spool opening characteristic is set such that the brake pressure gradually decreases as the spool of the control valve decreases, and the stop side of the control valve is adjusted in accordance with the spool opening characteristic. A delay means for delaying the return time to the power supply is provided.
[0018]
According to a seventh aspect of the present invention, in the configuration of the sixth aspect, a hydraulic pilot switching valve is used as the control valve, and a throttle is provided in a pilot line of the control valve as a delay unit.
[0019]
According to an eighth aspect of the present invention, in the configuration of the seventh aspect, a flow control valve for maintaining a constant flow rate through the throttle is provided.
[0020]
According to a ninth aspect of the present invention, in the configuration of any one of the first to eighth aspects, the meter-out opening characteristic of the control valve is set such that the meter-out opening becomes semi-open when the control valve is set to the stop position. It is a thing.
[0021]
In a crusher that is hydraulically driven and has hydraulic brake means, the maximum driving pressure of the hydraulic motor (pressure acting when the motor starts) is determined by the set crushing capacity (horsepower). Normally, a brake pressure equal to the maximum drive pressure acts.
[0022]
On the other hand, according to the above configuration, since the brake pressure by the hydraulic brake means is set to a value lower than the maximum drive pressure, the time required for stopping becomes longer but the load on the transmission mechanism becomes smaller.
[0023]
For this reason, it is possible to suppress the occurrence of troubles in the transmission mechanism at the time of stoppage (for example, generation of belt wear and loud slip noise due to slippage of the transmission belt in the belt transmission mechanism).
[0024]
By the way, the driving pressure of the hydraulic motor suddenly decreases when it enters a steady rotation after the start, and thereafter, the hydraulic motor is driven at this steady pressure.
[0025]
According to the configuration of the second aspect, the brake pressure is set to a value lower than the maximum drive pressure but higher than this steady pressure, so that the brake time required for stopping can be shortened as much as possible.
[0026]
In this case, in the third and fourth aspects, the set pressure of the brake side relief valve constituting the brake valve is set lower than the set pressure of the drive side relief valve, so that the brake pressure acts.
[0027]
In contrast, in claims 5 to 8, the brake pressure acts by the meter-out throttle when the spool of the control valve returns to the stop position.
[0028]
In this case, since the brake pressure gradually decreases as the stroke decreases, the hydraulic motor stops smoothly.
[0029]
In particular, according to the configuration of claim 8, the flow rate of the throttle as the delay means for narrowing the pilot line of the pilot switching control valve is kept constant by the flow control valve, so that the spool moves at a constant speed to the stop position side. Thus, a smoother motor stopping action can be obtained.
[0030]
According to the ninth aspect of the present invention, the meter-out opening is in a semi-open state (slightly open state) at the stop position, so that in the crusher in which the jaws are eccentrically mounted on the flywheel as described above, The wheel always rotates to the lowest point and stops. Therefore, it is possible to omit the trouble of positioning the flywheel at the lowest point when adjusting the gap between the jaws, and it is not necessary to add an extra configuration (such as a communication valve) for stopping at the lowest point.
[0031]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the present invention will be described with reference to FIGS.
[0032]
First embodiment (see FIGS. 1 and 2)
In the first embodiment, a crusher in which the hydraulic motor 5 rotates only in one direction and generates brake pressure on the braking side by a brake valve when stopped is applied.
[0033]
As shown in FIG. 1, an electromagnetic switching type control valve 11 is provided between a hydraulic motor 5 and a hydraulic pump 10 as a hydraulic pressure source, and a drive side pipe line 12 is provided between the control valve 11 and the hydraulic motor 5. And a brake circuit (counter balance valve) 19 composed of both drive-side and brake-side relief valves 15, 16 and check valves 17, 18. Is provided.
[0034]
In FIG. 1, 6 is a motor pulley, 7 is a transmission belt, 8 is a flywheel, 20 is a back pressure valve, and T is a tank.
[0035]
The control valve 11 has a drive position A and a stop position B. At the drive position A of the control valve 11, the hydraulic motor 5 rotates by the drive pressure acting on the drive side pipeline 12, The motor 5 is stopped by the brake pressure acting on the road 13.
[0036]
FIG. 2 shows the transition of the pressure from the start to the stop of the hydraulic motor 5. When the control valve 11 is set to the drive position A, a drive pressure P1 is generated in the drive side pipe 12, and the drive pressure P1 The rotation of the hydraulic motor 5 starts.
[0037]
This drive pressure rises to the maximum drive pressure P1max determined by the set pressure of the drive-side relief valve 15 to generate a start-up torque, and when it enters steady rotation, it falls to the steady pressure P2 which is considerably lower than the maximum drive pressure P1max.
[0038]
Then, when the control valve 11 is returned to the stop position B, a brake pressure P3 determined by the set pressure of the brake-side relief valve 16 is generated in the brake-side pipe line 13 as shown by a dashed line.
[0039]
In this case, conventionally, the set pressures of both the drive-side and brake-side relief valves 15 and 16 are set to be the same, and a maximum brake pressure (maximum value P3max) equal to that at the time of drive is generated at the time of stop. A large load acts on the belt transmission mechanism that transmits the force to the flywheel 8.
[0040]
On the other hand, in this crusher, the set pressure Pb of the brake side relief valve 16 is set to a value lower than the set pressure Pa (= P1max) of the drive side relief valve 15 (for example, 2/3 of the maximum drive pressure P1max). The brake pressure P3 ′ (maximum value P3′max) that is set and is lower than the maximum drive pressure P1max acts on the hydraulic motor 6 as shown by a broken line in FIG.
[0041]
By doing so, the time required for stopping the hydraulic motor 5 becomes longer, but the load on the power transmission belt 7 is reduced, so that the slip of the power transmission belt 7 is suppressed, and wear and slip noise of the power transmission belt 7 due to the slip are reduced. Generation is suppressed.
[0042]
Further, in this embodiment, as shown in FIG. 2, the brake pressure P3 'is set to a value higher than the steady pressure P2.
[0043]
By doing so, the braking time required for stopping can be shortened as much as possible, as compared with the case where the brake pressure P3 'is equal to or less than the steady pressure P2.
[0044]
Second embodiment (see FIG. 3)
In the second embodiment, the configuration of the first embodiment is applied to a circuit configuration for rotating the hydraulic motor 5 in both forward and reverse directions.
[0045]
Only differences from the first embodiment will be described.
[0046]
In the motor circuit 14, a control valve 21, which is an electromagnetic three-position switching valve having a forward rotation position A, a reverse rotation position B, and a neutral position C, and a brake valve 26 comprising a pair of relief valves 22, 23 and check valves 24, 25 The rotation direction of the hydraulic motor 5 is switched between forward and reverse by the control valve 21, and one of the relief valves 22, 23 is driven on the drive side and the other is on the brake side in accordance with the rotation direction of the motor.
[0047]
The two relief valves (hereinafter, referred to as first and second relief valves) 22 and 23 are configured as two-stage relief valves in which a set pressure changes between high and low levels according to pilot pressure. The lines 27 and 28 are provided with an electromagnetic switching type set pressure switching valve 29 for increasing the set pressure of the relief valve 22 or 23 on the drive side in accordance with the forward rotation and the reverse rotation of the hydraulic motor 5.
[0048]
The switching valve 29 has a forward rotation position A, a reverse rotation position B, and a neutral position C. The set pressure of the first relief valve 22 at the normal rotation position A, and the set pressure of the second relief valve 23 at the reverse rotation position B. Rise respectively.
[0049]
Reference numeral 30 denotes a pilot hydraulic pressure source, 31 denotes a forward rotation switch for switching the control valve 21 and the set pressure switching valve 29 to the forward rotation position A, and 32 denotes a reverse rotation switch for switching to the same reverse rotation position B.
[0050]
In this configuration, at the time of forward rotation of the motor, the set pressure switching valve 29 is switched to the forward rotation position A, and the first relief valve 22 on the driving side is set at a high pressure (relatively the second relief valve 23 is at a low pressure). At the time of reverse rotation, the switching valve 29 is switched to the reverse rotation position B, and the second relief valve 23 is set to a high pressure (relatively, the first relief valve 22 is set to a low pressure).
[0051]
Thus, in both forward and reverse rotations, the hydraulic motor 5 is stopped at a brake pressure lower than the maximum drive pressure to reduce the load on the power transmission belt 7 and to suppress wear and slip noise thereof.
[0052]
In the second embodiment, the set pressure on the drive side of the two relief valves 22 and 23 is set to be high, but the set pressure on the braking side may be set to be low.
[0053]
Third embodiment (see FIGS. 4 and 5)
In the third embodiment, instead of the method of generating the brake pressure by the brake valves 19 and 26 as in the first and second embodiments, a configuration in which the brake pressure is generated by a meter-out throttle of the control valve 33 is adopted. ing.
[0054]
That is, the motor circuit 14 is provided with only one relief valve 34 and the check valves 35 and 36 for determining the maximum drive pressure, while the meter-out opening of the control valve 33 is changed from the minimum stroke to the maximum stroke as shown in FIG. The spool opening characteristic is set so as to increase at a gentle slope in a section S1 slightly before the front side.
[0055]
According to the spool opening characteristics, the brake pressure gradually increases in the section S1 when the motor stops, so that the load on the transmission belt 7 can be reduced as in the first and second embodiments.
[0056]
However, when this configuration is adopted, it is necessary to return the control valve 33 to the stop side gently in accordance with the spool opening characteristics shown in FIG.
[0057]
Accordingly, the control valve 33 is of a hydraulic pilot switching type, and a pilot line 37 is provided with a switching control valve 38 for controlling the switching of the control valve 33 between the drive position a and the stop position b, and a tank T when the motor is stopped. A throttle 39 is provided as delay means for reducing the return pilot flow rate and securing the return time of the control valve 33 to the stop position B. 40 is a pilot hydraulic pressure source.
[0058]
Fourth embodiment (see FIG. 6)
In the third embodiment, since the pilot flow rate is reduced by only the throttle 39, there is a problem that the passing flow rate is not constant and the return speed of the control valve 33 changes.
[0059]
Therefore, in the fourth embodiment, a flow rate control valve (so-called flow control valve) 41 is provided downstream of the throttle 39 in the pilot line 37, and the flow rate through the throttle 39 is made constant by the differential pressure constant control action of the control valve 41. It has a configuration.
[0060]
In this case, the return speed of the control valve 33 becomes constant, and the meter-out opening decreases at a constant rate, so that a smooth braking action can be obtained.
[0061]
Fifth embodiment (see FIGS. 7 and 8)
In the crusher in which the jaw 9 is eccentrically attached to the flywheel 8 as shown in FIG. 10, unless the flywheel 8 stops at the lowest point, the jaw 9 may be adjusted when adjusting the jaw clearance to obtain a desired degree of crushing. It is necessary to position the flywheel 8 at the lowest point so that 9 does not fall.
[0062]
Alternatively, it is necessary to add extra means for automatically stopping the flywheel 8 at the lowest point (for example, a communication valve for connecting the motor circuit to the tank).
[0063]
In the fifth embodiment, as a measure against this point, the meter-out opening characteristic is set so that the meter-out opening remains slightly open (semi-open) even after the control valve 33 returns to the stop position B. . In FIG. 8, S2 is this semi-open section.
[0064]
In this way, even after the control valve 33 returns to the stop position B, the hydraulic motor 5 rotates until the flywheel 8 reaches the lowest point, so that the flywheel 8 is purposely positioned at the lowest point when adjusting the jaw clearance. This saves time and eliminates the need to add an extra configuration (such as a communication valve) for stopping at the lowest point.
[0065]
In the drawings, it is assumed that the third and fourth embodiments generate a brake pressure lower than the maximum drive pressure by the meter-out opening of the control valve 33. Can be applied to the first and second embodiments in which the same action is obtained by the brake valves 19 and 26 shown in FIG.
[0066]
In this case, the meter-out opening may be semi-open at the neutral position c of the control valve 21 in the first embodiment at the stop position b of the control valve 11, and the brake valve 19, After the braking action by the function 26 is performed, the final motor rotating action by the semi-open meter-out opening is performed at the stop position B or the neutral position C.
[0067]
By the way, in each of the third to fifth embodiments, the case where the hydraulic motor 5 is rotated in one direction is illustrated, but the configuration of these embodiments can also be applied to the case where the hydraulic motor 5 is rotated forward and backward.
[0068]
Further, in each of the above embodiments, the case where the belt transmission mechanism is used as the transmission mechanism for transmitting the rotational force of the hydraulic motor to the crushing unit has been described. However, the present invention is not limited to the case where another transmission mechanism (for example, a chain transmission mechanism, a gear transmission mechanism) is used. Etc.) can be carried out in the same manner as described above.
[0069]
【The invention's effect】
As described above, according to the present invention, since the brake pressure lower than the maximum drive pressure is applied when the motor is stopped, the load on the transmission mechanism can be reduced.
[0070]
For this reason, it is possible to suppress the occurrence of troubles in the transmission mechanism at the time of stoppage (for example, generation of belt wear and loud slip noise due to slippage of the transmission belt in the belt transmission mechanism).
[0071]
In this case, according to the second aspect of the invention, the brake pressure is set to a value lower than the maximum drive pressure but higher than the steady pressure, so that the brake time required for stopping can be shortened as much as possible.
[0072]
According to the invention of claim 8, when the spool opening characteristic of the control valve is set so that a brake pressure lower than the maximum driving pressure is generated, the spool is stroked at a constant speed to the stop position side to achieve a smoother operation. A motor stopping action can be obtained.
[0073]
According to the ninth aspect of the present invention, since the meter-out opening is in a semi-open state at the stop position, the flywheel can always be stopped at the lowest point in the crusher in which the jaw is eccentrically mounted on the flywheel. it can. Therefore, it is possible to omit the trouble of positioning the flywheel at the lowest point when adjusting the gap between the jaws, and it is not necessary to add an extra configuration (such as a communication valve) for stopping at the lowest point.
[Brief description of the drawings]
FIG. 1 is a hydraulic circuit diagram showing a first embodiment of the present invention.
FIG. 2 is a characteristic diagram of a motor driving pressure and a brake pressure for explaining a braking operation according to the embodiment.
FIG. 3 is a hydraulic circuit diagram showing a second embodiment of the present invention.
FIG. 4 is a hydraulic circuit diagram showing a third embodiment of the present invention.
FIG. 5 is a characteristic diagram of a spool opening of the control valve according to the embodiment.
FIG. 6 is a hydraulic circuit diagram showing a fourth embodiment of the present invention.
FIG. 7 is a view showing a control valve according to a fifth embodiment of the present invention.
FIG. 8 is a characteristic diagram of a spool opening of the control valve.
FIG. 9 is an overall schematic side view of a mobile crusher to which the present invention is applied.
FIG. 10 is a configuration diagram of a drive system in the crusher.
[Explanation of symbols]
5 Hydraulic Motor 6 Drive Pulley 7 Constituting Transmission Mechanism 7 Transmission Belt 8 Flywheel 9 at Crushing Section 9 Jaws 10 Hydraulic Pumps 11 and 21 Control Valves 12 and 13 Motor Side Pipelines 14 Motor Circuits 19 and 26 Brake Valves 15 and 16 , 22, 23 Relief valve 33 constituting brake valve Control valve 37 also serving as hydraulic brake means Pilot line 39 of the control valve 39 Restrictor 41 as delay means Flow control valve

Claims (9)

In a hydraulically driven crusher provided with a hydraulic brake means for transmitting a rotational force of a hydraulic motor to a crushing unit by a transmission mechanism to perform a crushing operation and generating a brake pressure on the braking side of the hydraulic motor when stopped, A hydraulically driven crusher, wherein a brake pressure by a hydraulic brake means is set to a value lower than a maximum driving pressure of the motor. 2. The hydraulically driven crusher according to claim 1, wherein the brake pressure is set to a value higher than the drive pressure during steady rotation of the hydraulic motor. 3. The hydraulically driven crusher according to claim 1, wherein the hydraulic circuit includes a hydraulic motor and a hydraulic pump serving as a hydraulic pressure source of the motor. A brake valve including a valve and a relief valve serving as a braking side is provided, and a set pressure of the brake side relief valve in the brake valve is set to a value lower than a set pressure of the drive side relief valve. Hydraulically driven crusher. 4. The hydraulically driven crusher according to claim 3, wherein a two-stage relief valve whose set pressure can be switched between a high level and a low level is used as both relief valves, and a braking side relief valve according to forward and reverse rotation of the hydraulic motor. A hydraulically driven crusher, characterized in that relief valve control means for controlling both relief valves is provided such that the set pressure of the drive side relief valve also becomes lower. 3. The hydraulically driven crusher according to claim 1, wherein a motor circuit connecting the hydraulic motor and a hydraulic pump as a hydraulic source of the motor also serves as control means for controlling rotation of the hydraulic motor and hydraulic brake means. A control valve is provided, and the spool opening characteristic of the control valve is set so that the brake pressure acting on the hydraulic motor is lower than the maximum drive pressure of the motor when the control valve is operated to the stop position. A hydraulically driven crusher characterized by the following. The hydraulically driven crusher according to claim 5, wherein the spool opening characteristic is set so that the brake pressure gradually decreases as the spool of the control valve decreases, and the control valve is moved to the stop side in accordance with the opening characteristic of the spool. A hydraulically driven crusher, wherein a delay means for delaying a return time is provided. 7. The hydraulically driven crusher according to claim 6, wherein a hydraulic pilot switching valve is used as a control valve, and a throttle is provided in a pilot line of the control valve as delay means. 8. The hydraulically driven crusher according to claim 7, further comprising a flow control valve for maintaining a constant flow rate through the throttle. The hydraulically driven crusher according to any one of claims 1 to 8, wherein a meter-out opening characteristic of the control valve is set such that the meter-out opening is semi-open when the control valve is set to the stop position. A hydraulically driven crusher, characterized in that:

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