CN111845677A - Reverse-dragging retarding braking system and self-propelled aerial working vehicle - Google Patents
Reverse-dragging retarding braking system and self-propelled aerial working vehicle Download PDFInfo
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- CN111845677A CN111845677A CN202010701292.7A CN202010701292A CN111845677A CN 111845677 A CN111845677 A CN 111845677A CN 202010701292 A CN202010701292 A CN 202010701292A CN 111845677 A CN111845677 A CN 111845677A
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- 230000000979 retarding effect Effects 0.000 title claims abstract description 13
- 230000007246 mechanism Effects 0.000 claims abstract description 38
- 239000003921 oil Substances 0.000 claims description 56
- 238000006073 displacement reaction Methods 0.000 claims description 23
- 230000001105 regulatory effect Effects 0.000 claims description 7
- 239000010720 hydraulic oil Substances 0.000 claims description 4
- 238000012544 monitoring process Methods 0.000 claims description 4
- 230000001276 controlling effect Effects 0.000 claims description 3
- 238000010276 construction Methods 0.000 claims description 2
- 230000005540 biological transmission Effects 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000005381 potential energy Methods 0.000 description 2
- 230000004075 alteration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000009347 mechanical transmission Effects 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
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- 238000006467 substitution reaction Methods 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
- B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
- B60T13/12—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid
- B60T13/16—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid using pumps directly, i.e. without interposition of accumulators or reservoirs
- B60T13/18—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid using pumps directly, i.e. without interposition of accumulators or reservoirs with control of pump output delivery, e.g. by distributor valves
Abstract
The invention discloses a reverse-dragging retarding braking system and a self-propelled aerial work vehicle, wherein the reverse-dragging retarding braking system comprises: the closed pump assembly is connected with an output shaft of a prime motor, the open pump assembly comprises a variable pump, a variable control mechanism and a variable mechanism, the variable pump is connected with the closed pump assembly in series through the output shaft, the variable control mechanism is used for sensing load feedback pressure and controlling the variable mechanism to adjust the outlet flow of the variable pump according to the pressure difference between the outlet pressure of the variable pump and the load feedback pressure, and when a vehicle is in a back-dragging working condition, the pressure adjusting device adjusts the outlet pressure and the load feedback pressure to enable the outlet flow of the variable pump to be maximum so as to provide large back-dragging torque; the self-propelled aerial working truck is provided with the reverse-dragging retarding braking system. The open type pump is effectively utilized under the back dragging working condition by adding the pressure adjusting device so as to provide enough back dragging torque, and the realization of the original arm support function is not influenced.
Description
Technical Field
The invention relates to the field of engineering machinery, in particular to a reverse-dragging retarding braking system and a self-propelled aerial work vehicle.
Background
In recent years, with the development of hydraulic transmission technology, more and more construction machines are beginning to adopt a traveling hydraulic system. Compared with mechanical transmission, the hydraulic transmission is easier to realize the control of motion parameters and power parameters, and has the advantages of high transmission efficiency, stepless speed regulation of output rotating speed, high speed rigidity, easy realization of action and the like.
The closed type walking hydraulic system of the existing self-propelled aerial working platform consists of a walking control valve, a closed type pump and a hydraulic motor driven by the closed type pump, and the walking hydraulic system realizes the walking control of the hydraulic motor through a synchronizing valve. When the self-propelled aerial work platform is on a downhill slope, the resisting torque of the closed pump and the engine provides the anti-dragging torque of the vehicle together, but when the slope exceeds 45% of the slope, the anti-dragging torque is insufficient, so that the downhill running speed of the self-propelled aerial work platform is faster and faster, the stall phenomenon occurs due to uncontrollable operation, and the self-propelled aerial work platform is greatly potential safety hazard due to the existence of the problem.
Disclosure of Invention
The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides a reverse-dragging retarding braking system for downhill stall prevention control of a self-propelled aerial work vehicle and the self-propelled aerial work vehicle comprising the reverse-dragging retarding braking system.
According to an embodiment of the invention, the anti-drag slow-speed braking system comprises: closed pump assembly, open pump assembly, pressure regulating device. The input end of the closed pump assembly is connected to the output shaft of the prime mover M1 of the self-propelled aerial work platform, and the closed pump assembly is used for providing hydraulic oil for a walking hydraulic system; the open type pump assembly comprises a variable pump, a variable control mechanism and a variable mechanism, wherein the variable pump is connected with the closed type pump assembly in series through the output shaft, and the variable control mechanism is used for sensing the load feedback pressure of the boom hydraulic system and controlling the variable mechanism to adjust the outlet flow of the variable pump according to the pressure difference between the outlet pressure of the variable pump and the load feedback pressure; and the pressure adjusting device is arranged in the boom hydraulic system, is respectively connected with the variable pump and the variable control mechanism, and is used for adjusting the outlet pressure and the load feedback pressure when the self-propelled aerial working truck is in a back-dragging work condition and the walking speed exceeds a monitoring value.
According to the anti-drag slow-release braking system of the embodiment of the invention, at least the following beneficial effects are achieved: the pressure regulating device is arranged to regulate the outlet pressure of the open pump assembly and the load feedback pressure of the boom hydraulic system, and the variable control mechanism controls the variable mechanism to regulate the outlet flow of the variable pump to the maximum according to the regulated pressure difference, so that the closed pump assembly, the open pump assembly and the prime motor M1 can jointly form a large enough anti-dragging torque.
According to some embodiments of the invention, the variable displacement pump is a swash plate type plunger pump.
According to some embodiments of the present invention, the variable mechanism is a variable piston, a rod chamber of the variable piston is provided with a return spring, a piston rod of the variable piston is mechanically connected to a swash plate of the variable pump, and a rod-free chamber of the variable piston is connected to the variable control mechanism through an oil passage.
According to some embodiments of the present invention, the variable control mechanism includes a pressure cut-off valve, a load sensitive valve, a first hydraulic resistance R1, a second hydraulic resistance R2, and a third hydraulic resistance R3, a working port a2 and a control port K3 of the pressure cut-off valve, and a working port a1 and a control port K1 of the load sensitive valve are all connected to an outlet of the variable pump, a working port T2 of the pressure cut-off valve is respectively connected to a working port T1 of the load sensitive valve and a rodless cavity of the variable piston, the first hydraulic resistance R1 and the second hydraulic resistance R2 are connected in series between a working port T2 of the pressure cut-off valve and an oil return tank, a second hydraulic resistance R2 is connected in series between a working port B2 of the pressure cut-off valve and the oil return tank, a working port B1 of the load sensitive valve is connected to the oil return tank, and the control port K2 of the load sensitive valve is connected to the pressure regulating device, and the third hydraulic resistance R3 is connected in series between the oil control port K2 of the load sensitive valve and the oil return tank.
According to some embodiments of the invention, the pressure control device comprises a first overflow valve, an electromagnetic directional valve and a one-way valve, an oil inlet of the first overflow valve is respectively connected with the variable control mechanism and the load of the boom hydraulic system through the one-way valve, an oil outlet of the first overflow valve is connected with the oil return tank, an oil inlet of the electromagnetic directional valve is connected with an outlet of the variable pump, and an oil outlet of the electromagnetic directional valve is connected with an oil inlet of the first overflow valve.
According to some embodiments of the invention, the first relief valve is an electro-hydraulic proportional relief valve.
According to some embodiments of the invention, the electromagnetic directional valve is a two-position, two-way directional valve.
According to some embodiments of the invention, an emergency power unit is connected in parallel to an oil path between the oil inlet of the electromagnetic directional valve and the outlet of the variable pump.
According to some embodiments of the invention, the first overflow valve, the electromagnetic directional valve and the one-way valve are all integrated in a boom control valve head joint, the boom control valve head joint further comprises a second overflow valve, an oil inlet of the second overflow valve is connected with an outlet of the variable pump through a filter, an oil outlet of the second overflow valve is connected with the oil return tank, and the overflow pressure of the first overflow valve is smaller than the overflow pressure of the second overflow valve.
Based on the same invention concept, the invention also provides a self-propelled aerial work vehicle which is provided with the anti-dragging retarding braking system in the embodiment.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Drawings
The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
fig. 1 is a hydraulic control schematic diagram of an embodiment of the present invention.
Reference numerals:
a closed pump assembly 100;
an open pump assembly 200, a variable displacement pump 201;
a variable control mechanism 202, a pressure cut-off valve 2021, a load sensitive valve 2022, and a variable mechanism 203;
a pressure adjusting device 300, a first overflow valve 301, an electromagnetic directional valve 302, and a check valve 303;
an emergency power unit 400;
the boom control valve is connected with the head 500 and a second overflow valve 501.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention.
In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.
In the description of the present invention, unless otherwise explicitly defined, terms such as arrangement, installation, connection and the like should be broadly construed, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the detailed contents of the technical solutions.
Referring to fig. 1, a reverse-towing retarding brake system according to an embodiment of the present invention includes: closed pump assembly 100, open pump assembly 200, pressure regulating device 300.
The input end of the closed pump assembly 100 is connected to the output shaft of the prime mover M1 of the self-propelled aerial work platform, and the closed pump assembly 100 is used for providing hydraulic oil for a walking hydraulic system;
the open type pump assembly 200 is used for providing hydraulic oil for the boom hydraulic system, when the self-propelled aerial working vehicle is in a walking working condition, the open type pump assembly 200 is in a minimum displacement low-pressure unloading state, and at the moment, the anti-dragging torque provided by the open type pump assembly 200 is small.
The open type pump assembly 200 comprises a variable pump 201, a variable control mechanism 202 and a variable mechanism 203, wherein the variable pump 201 is connected with the closed type pump assembly 100 in series through an output shaft of a prime motor M1, and when the self-propelled aerial work platform is in a reverse towing working condition, a reverse towing moment is formed by the closed type pump assembly 100, the open type pump assembly 200 and the prime motor M1 together. The variable control mechanism 202 is used for sensing the load feedback pressure of the boom hydraulic system and controlling the variable mechanism 203 to adjust the outlet flow of the variable pump 201 according to the pressure difference between the outlet pressure of the variable pump 201 and the load feedback pressure.
The pressure adjusting device 300 is installed in the boom hydraulic system and is respectively connected with the variable pump 201 and the variable control mechanism 202, when the self-propelled aerial work vehicle is in a back-dragging condition and the walking speed exceeds a monitoring value, the pressure adjusting device 300 adjusts the outlet pressure of the variable pump 201 and the load feedback pressure of the boom hydraulic system to enable the variable control mechanism 202 to control the variable mechanism 203 to adjust the outlet flow of the variable pump 201 to the maximum, so that the function that the open type pump assembly 200 provides a large back-dragging torque is realized, in addition, when the self-propelled aerial work vehicle is in other working conditions, the pressure adjusting device 300 does not work, and therefore the realization of the original boom function is not influenced.
It should be noted that the above-mentioned anti-dragging operating condition refers to: when the self-propelled overhead working truck runs on a downhill, usually, an engine is in an idling state, the power output by the engine only needs to meet the work of a suspension hydraulic system, a steering hydraulic system, a generator and the like, the energy of the downhill running of the vehicle comes from gravitational potential energy, the gravitational potential energy is transmitted to the engine through a motor and a walking pump through wheels, and at the moment, the motor works under the pump working condition, and the walking pump works under the motor working condition.
In some embodiments of the present invention, the variable displacement pump 201 is a swash plate type plunger pump, and the inclination angle of the swash plate of the variable displacement pump 201 is controlled by the variable displacement mechanism 203, so as to change the outlet flow rate of the variable displacement pump 201.
In some embodiments of the present invention, the variable displacement mechanism 203 is a variable displacement piston having a rod chamber provided with a return spring, the piston rod of the variable displacement piston being mechanically connected to the swash plate of the variable displacement pump 201, and the rod-less chamber of the variable displacement piston being connected to the variable displacement control mechanism 202 via an oil passage.
In some embodiments of the present invention, the variable control mechanism 202 includes a pressure shut-off valve 2021, a load sensitive valve 2022, a first hydraulic resistance R1, the second hydraulic resistance R2, the third hydraulic resistance R3, a working port a2 and a control port K3 of the pressure cut-off valve 2021, and a working port a1 and a control port K1 of the load sensitive valve 2022 are all connected to the outlet of the variable displacement pump 201, a working port T2 of the pressure cut-off valve 2021 is respectively connected to a working port T1 of the load sensitive valve 2022 and a rodless cavity of the variable piston, a first hydraulic resistance R1 and a second hydraulic resistance R2 are connected in series between the working port T2 of the pressure cut-off valve 2021 and the oil return tank, a second hydraulic resistance R2 is connected in series between the working port B2 of the pressure cut-off valve 2021 and the oil return tank, a working port B1 of the load sensitive valve 2022 is connected to the oil return tank, the oil control port K2 of the load sensitive valve 2022 is connected to the pressure regulating device 300, and a third hydraulic resistance R3 is connected in series between the oil control port K2 of the load sensitive valve 202.
The pressure cut-off valve 2021 is used to set the maximum working pressure of the boom hydraulic system, and the load sensitive valve 2022 compares the difference between the outlet pressure of the variable pump 201 and the load feedback pressure, so as to make the swash plate angle of the variable pump 201 swing within the range from zero to the maximum angle (the corresponding variable pump 201 is at the minimum displacement to the maximum displacement). When the outlet pressure of the variable pump 201 reaches the set pressure of the pressure cut-off valve 2021, the pressure cut-off valve 2021 is in the left position, the high-pressure oil at the outlet of the variable pump 201 enters the rodless cavity of the variable piston, so that the variable piston moves leftwards, the swash plate is pushed to turn to the minimum displacement position, and at the moment, the output flow of the variable pump 201 is reduced, so that the overload of the boom hydraulic system is prevented. When the difference between the pressure at the port B and the pressure at the port X of the open pump assembly 200 becomes large, the load-sensitive valve 2022 is in the left position, and high-pressure oil enters the rodless cavity of the variable piston to push the piston to drive the swash plate to rotate to the minimum displacement position.
The arrangement of the first hydraulic resistance R1, the second hydraulic resistance R2 and the third hydraulic resistance R3 improves the rapidity and the stability of variable control by the aid of the hydraulic resistances formed by the first hydraulic resistance R1, the second hydraulic resistance R2 and the third hydraulic resistance R3 in the process of increasing displacement.
In some embodiments of the present invention, the pressure control device 300 includes a first overflow valve 301, an electromagnetic directional valve 302, and a check valve 303, an oil inlet of the first overflow valve 301 is connected to the variable control mechanism 202 and the load of the boom hydraulic system through the check valve 303, an oil outlet of the first overflow valve 301 is connected to an oil return tank, an oil inlet of the electromagnetic directional valve 302 is connected to an outlet of the variable pump 201, and an oil outlet of the electromagnetic directional valve 302 is further connected to an oil inlet of the first overflow valve 301.
When the self-propelled aerial working truck normally runs or the arm support is opened to act, the electromagnetic directional valve 302 is not electrified, and the first overflow valve 301 does not work, so that the original function of the arm support hydraulic system is not affected. When the self-propelled overhead working truck is in an anti-dragging condition and the walking speed exceeds a monitoring value, the electromagnetic directional valve 302 is electrified, the first overflow valve 301 acts, the pressure stop valve 2021 and the load sensitive valve 2022 are both in the right position at the moment, the rodless cavity of the variable piston is decompressed through the oil port L of the open type pump assembly 200, the variable piston moves rightwards at the moment, under the action of the spring force of the reset spring, the swash plate of the variable pump 201 is pushed to the maximum displacement position, so that the variable pump 201 provides a large moment to prevent the engine from being dragged and accelerated, and the stable downhill of the whole truck is realized.
In some embodiments of the present invention, the first overflow valve 301 is an electro-hydraulic proportional overflow valve, so that different overflow pressure values can be set remotely, and it should be noted that the first overflow valve may adopt other adjustable overflow valves.
In some embodiments of the present invention, the electromagnetic directional valve 302 is a two-position two-way directional valve, and it should be noted that other hydraulic valves capable of achieving similar effects are also possible.
In some embodiments of the invention, an emergency power unit 400 is connected in parallel to an oil path between an oil inlet of the electromagnetic directional valve 302 and an outlet of the variable displacement pump 201, so that the normal operation of the boom hydraulic system is guaranteed in the case of failure of the prime mover M1.
In some embodiments of the invention, the first overflow valve 301, the electromagnetic directional valve 302, and the check valve 303 are all integrated in the boom control valve head 500, the boom control valve head 500 further includes a second overflow valve 501, an oil inlet of the second overflow valve 501 is connected to an outlet of the variable displacement pump 201 through a filter, an oil outlet of the second overflow valve 501 is connected to an oil return tank, and an overflow pressure of the first overflow valve 301 is smaller than an overflow pressure of the second overflow valve 501.
The invention also provides a self-propelled aerial working vehicle which is provided with the reverse-dragging retarding braking system in the embodiment.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.
Claims (10)
1. The utility model provides a drag slow braking system backward for self-propelled high altitude construction car which characterized in that includes:
the closed pump assembly (100), the input end of the closed pump assembly (100) is connected to the output shaft of the prime mover M1 of the self-propelled aerial work platform truck, and the closed pump assembly (100) is used for providing hydraulic oil for a walking hydraulic system;
the open type pump assembly (200) comprises a variable pump (201), a variable control mechanism (202) and a variable mechanism (203), wherein the variable pump (201) is connected with the closed type pump assembly (100) in series through the output shaft, the variable control mechanism (202) is used for sensing the load feedback pressure of the boom hydraulic system and controlling the variable mechanism (203) to adjust the outlet flow of the variable pump (201) according to the pressure difference between the outlet pressure of the variable pump (201) and the load feedback pressure;
the pressure adjusting device (300) is installed in the arm support hydraulic system, is respectively connected with the variable pump (201) and the variable control mechanism (202), and is used for adjusting the outlet pressure and the load feedback pressure when the self-propelled aerial work vehicle is in an anti-dragging work condition and the walking speed exceeds a monitoring value.
2. Anti-drag slow brake system according to claim 1, characterized in that the variable pump (201) is a swash plate type plunger pump.
3. The anti-drag slow braking system according to claim 2, characterized in that the variable mechanism (203) is a variable piston, a rod chamber of the variable piston is provided with a return spring, a piston rod of the variable piston is mechanically connected with a swash plate of the variable pump (201), and a rodless chamber of the variable piston is connected with the variable control mechanism (202) through an oil path.
4. The anti-drag retarding brake system according to claim 3, wherein the variable control mechanism (202) comprises a pressure cut-off valve (2021), a load sensitive valve (2022), a first hydraulic resistance R1, a second hydraulic resistance R2 and a third hydraulic resistance R3, a working port A2 and a control port K3 of the pressure cut-off valve (2021) and a working port A1 and a control port K1 of the load sensitive valve (2022) are connected with an outlet of the variable pump (201), a working port T2 of the pressure cut-off valve (2021) is respectively connected with a working port T1 of the load sensitive valve (2022) and a rodless cavity of the variable piston, the first hydraulic resistance R1 and the second hydraulic resistance R2 are connected in series between a working port T2 of the pressure cut-off valve (2021) and an oil return tank, and a second hydraulic resistance R2 is connected in series between a working port B2 of the pressure cut-off valve (2021) and the oil return tank, a working oil port B1 of the load sensitive valve (2022) is connected with the oil return tank, an oil control port K2 of the load sensitive valve (2022) is connected with the pressure regulating device (300), and a third hydraulic resistance R3 is connected in series between the oil control port K2 of the load sensitive valve (2022) and the oil return tank.
5. The anti-drag retarding braking system according to claim 1, wherein the pressure control device (300) comprises a first overflow valve (301), an electromagnetic directional valve (302) and a one-way valve (303), an oil inlet of the first overflow valve (301) is connected with the variable control mechanism (203) and the load of the boom hydraulic system through the one-way valve (303), an oil outlet of the first overflow valve (301) is connected with the oil return tank, an oil inlet of the electromagnetic directional valve (302) is connected with an outlet of the variable pump (201), and an oil outlet of the electromagnetic directional valve (302) is connected with an oil inlet of the first overflow valve (301).
6. Anti-drag retard brake system according to claim 5, characterized in that the first overflow valve (301) is an electro-hydraulic proportional overflow valve.
7. The anti-drag slow brake system according to claim 5, characterized in that the electromagnetic directional valve (302) is a two-position, two-way directional valve.
8. The anti-drag slow braking system according to claim 5, characterized in that an emergency power unit (400) is connected in parallel to an oil path between an oil inlet of the electromagnetic directional valve (302) and an outlet of the variable displacement pump (201).
9. The anti-drag slow braking system according to claim 5, wherein the first overflow valve (301), the electromagnetic directional valve (302) and the check valve (303) are integrated in a boom control valve head (500), the boom control valve head (500) further comprises a second overflow valve (501), an oil inlet of the second overflow valve (501) is connected with an outlet of the variable pump (201) through a filter, an oil outlet of the second overflow valve (501) is connected with the oil return tank, and the overflow pressure of the first overflow valve (301) is smaller than the overflow pressure of the second overflow valve (501).
10. A self-propelled aerial work vehicle, characterised in that a backhoe retarder brake system as claimed in any one of claims 1 to 9 is provided.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010701292.7A CN111845677A (en) | 2020-07-20 | 2020-07-20 | Reverse-dragging retarding braking system and self-propelled aerial working vehicle |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010701292.7A CN111845677A (en) | 2020-07-20 | 2020-07-20 | Reverse-dragging retarding braking system and self-propelled aerial working vehicle |
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| CN111845677A true CN111845677A (en) | 2020-10-30 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010701292.7A Pending CN111845677A (en) | 2020-07-20 | 2020-07-20 | Reverse-dragging retarding braking system and self-propelled aerial working vehicle |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112796689A (en) * | 2021-02-03 | 2021-05-14 | 江苏中煤矿山设备有限公司 | Pressure-adjustable pump truck for punching and drilling |
| CN114087243A (en) * | 2021-11-12 | 2022-02-25 | 杭州中车车辆有限公司 | Straddle type monorail engineering vehicle and hydraulic system |
-
2020
- 2020-07-20 CN CN202010701292.7A patent/CN111845677A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112796689A (en) * | 2021-02-03 | 2021-05-14 | 江苏中煤矿山设备有限公司 | Pressure-adjustable pump truck for punching and drilling |
| CN114087243A (en) * | 2021-11-12 | 2022-02-25 | 杭州中车车辆有限公司 | Straddle type monorail engineering vehicle and hydraulic system |
| CN114087243B (en) * | 2021-11-12 | 2022-09-30 | 杭州中车车辆有限公司 | Straddle type monorail engineering vehicle and hydraulic system |
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