A new cab tilt control system and wheel crane

Abstract

This utility model discloses a novel operator's cab pitch control system and a wheeled crane, belonging to the field of crane technology, aiming to solve the design problem of pitch function in small-tonnage wheeled cranes. It includes: a pilot unit, an operator's cab pitch control valve installed on the pilot unit's hydraulic circuit, and an operator's cab pitch cylinder connected to the pilot unit's pitch control valve. The operator's cab pitch control valve is a three-position four-way solenoid valve with three valve positions and an inlet, a return port, a first outlet, and a second outlet. The first and second outlets are connected to the rod-side and rodless-side chambers of the operator's cab pitch cylinder respectively through an operator's cab pitch balance valve, used to control the extension and retraction of the operator's cab pitch cylinder to achieve the operator's cab pitch function. This utility model can achieve the operator's cab pitch function without adding an auxiliary pump, while simultaneously preventing the operator's cab from automatically falling and balancing and buffering the impact force of the operator's cab pitch cylinder through the operator's cab pitch balance valve.

Description

Technical Field

[0001] This utility model relates to a novel operator's cab pitch control system and a wheeled crane, belonging to the field of wheeled cranes. Background Technology

[0002] Due to their specialized function, truck cranes often require operators to look up at the load on the hook. To increase operator comfort, large-tonnage vehicles are equipped with a cab lifting function, while smaller-tonnage vehicles, due to cost constraints, have fewer models equipped with a cab tilt function. Because large-tonnage vehicles have counterweight lifting, air conditioning, and other auxiliary systems, they are designed with auxiliary pumps and valves to control these systems, such as the auxiliary control valve disclosed in patent CN203529752U. Adding a cab tilt system to large-tonnage vehicles requires additional auxiliary valves to control the cab's tilt.

[0003] However, for existing small-tonnage vehicles, taking a 25-ton vehicle as an example, there are only a main pump, a rotary pump, and a pilot pump. Adding an auxiliary pump would not only make chassis layout difficult but also increase costs. Although some existing technologies employ designs without auxiliary valves, such as the concept disclosed in patent CN117342429A that uses an airbag and inflation system to replace the auxiliary valve for achieving cab pitch, this design requires a separate inflation system, which is costly. Therefore, achieving cab pitch functionality in small-tonnage vehicles without adding an auxiliary pump and reducing overall costs is a current challenge in product design. Utility Model Content

[0004] Purpose of the utility model: The purpose of this utility model is to overcome the shortcomings of the prior art and provide a new type of operator's cab pitch control system and wheeled crane, which can solve the problem of adding operator's cab pitch function to cranes without auxiliary functions, and achieve operator's cab pitch function without adding an auxiliary pump.

[0005] To solve the above-mentioned technical problems, this utility model is implemented using the following technical solution:

[0006] In the first aspect, this utility model provides a novel cockpit pitch control system, comprising: a pilot unit, a cockpit pitch control valve disposed on the oil circuit of the pilot unit, and a cockpit pitch cylinder connected to the cockpit pitch control valve;

[0007] The pitch control valve in the control room is a three-position four-way solenoid valve with three valve positions and an oil inlet, an oil return port, a first oil outlet, and a second oil outlet.

[0008] The first oil outlet and the second oil outlet are connected to the rod chamber and rodless chamber of the control room pitch cylinder respectively through the control room pitch balance valve, and are used to control the extension and retraction of the control room pitch cylinder to realize the control room pitch function.

[0009] Optionally, the pilot unit includes a pilot pump and a pilot valve; the oil outlet of the pilot pump is connected to the oil inlet of the pitch control valve in the control room, and the oil inlet of the pilot pump is connected to the oil tank.

[0010] The inlet of the pilot valve is connected to the return port of the pitch control valve in the control room.

[0011] Optionally, an overflow valve is provided at the oil inlet of the control room pitch control valve. The oil inlet of the overflow valve is connected to the oil outlet of the pilot pump, and the oil outlet of the overflow valve is connected to the oil inlet of the pilot valve and the oil return port of the control room pitch control valve.

[0012] Optionally, the control terminal of the operator's cab pitch control valve is electrically connected to the controller for switching the position of the operator's cab pitch control valve.

[0013] Optionally, the three valve positions of the control room pitch control valve include a left position, a middle position, and a right position;

[0014] When the control room pitch control valve is in the neutral position, the control room pitch control valve is not connected to the control room pitch cylinder;

[0015] When the control room pitch control valve is in the right position, oil is supplied to the rodless chamber of the control room pitch cylinder through the control room pitch balance valve at port B, causing the control room pitch cylinder to extend.

[0016] When the control room pitch control valve is in the left position, oil is supplied to the rod chamber of the control room pitch cylinder through the control room pitch balance valve at port A, causing the control room pitch cylinder to retract.

[0017] Optionally, the control room pitch balance valve includes a first oil inlet and a second oil inlet. The second oil inlet includes a check valve and a pilot-operated sequence valve. When oil enters through the second oil inlet, hydraulic oil enters through the check valve and returns through the first oil inlet. When oil enters through the first oil inlet, the hydraulic oil acts as a pilot pressure to open the pilot sequence valve, allowing oil to return through the pilot sequence valve.

[0018] The pilot port of the balance valve is set at the first oil inlet of the balance valve and the rod chamber oil port of the control room pitch cylinder through the pilot oil circuit, and the first oil inlet of the balance valve is connected to the first oil outlet of the control room pitch control valve.

[0019] The second oil inlet of the balance valve is connected to the rodless chamber oil port of the pitch cylinder of the control room, and the second oil inlet of the balance valve is connected to the second oil outlet of the pitch control valve of the control room.

[0020] Optionally, an overflow valve is provided on the oil line of the P port of the control room pitch control valve;

[0021] The relief valve needs to match the maximum pitch pressure of the control room and the pressure of the pilot control valve, so that the pressure does not exceed the maximum pressure that the gear pump can withstand, while the control room can pitch normally.

[0022] Secondly, this utility model provides a wheeled crane, the control system described above being installed on the operator's cab.

[0023] Beneficial effects: Compared with the prior art, this utility model has the following advantages:

[0024] The pilot unit's hydraulic circuit includes a cab pitch control valve and a cab pitch cylinder connected to it. The pilot unit provides pilot pressure to the entire vehicle and supplies hydraulic oil to the cab for pitch control. The cab pitch control valve is connected in series in the pilot hydraulic circuit. By switching the pilot oil supply to the cab pitch cylinder, the extension and retraction of the cab pitch cylinder can be achieved. This allows the cab pitch function to be realized without adding an auxiliary pump. To prevent the cab from falling automatically, a cab pitch balance valve is added to stabilize the cab pitch cylinder and provide balance and buffering.

[0025] To prevent excessive pressure in the pitch cylinder of the control room, an overflow valve is installed at the pressure port of the pitch control valve in the control room. This valve can stabilize the pressure in the pitch cylinder of the control room and also help improve the pitch control accuracy and response speed of the control room, thereby improving the overall performance of the equipment. Attached Figure Description

[0026] Figure 1 The diagram shown is a structural diagram of a conventional operator's cab landing control system.

[0027] Figure 2 The diagram shown is a structural schematic of the novel control room pitch control system provided in this embodiment.

[0028] In the diagram: 1-pilot pump, 2-pilot valve, 3-control room pitch control valve, 4-control room pitch balance valve, 5-control room pitch cylinder, 1a-auxiliary pump, 2a-auxiliary valve, 3a-existing control room pitch balance valve, 4a-existing control room pitch cylinder. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0030] like Figure 1The diagram shows a conventional cockpit lifting and lowering control system, including an auxiliary pump 1a, an auxiliary valve 2a, a conventional cockpit pitch balance valve 3a, and a conventional cockpit pitch cylinder 4a. The auxiliary pump 1a supplies oil to the auxiliary valve 2a, which distributes different actions. The cockpit pitch function is controlled by energizing and de-energizing the cockpit pitch solenoid valves Y1, Y2, and Y3. When Y3 and Y2 are energized, hydraulic oil enters the V2 port of the conventional cockpit pitch balance valve 3a through port A2, and then enters the rodless chamber of the cockpit pitch cylinder, causing the cockpit pitch cylinder to extend and the cockpit to lift. When Y3 and Y1 are energized, hydraulic oil enters the V1 port of the cockpit pitch balance valve 3a through port B2, and then enters the rod chamber of the cockpit pitch cylinder, causing the cockpit pitch cylinder to retract and the cockpit to lower, thus achieving pitch control. However, this type of design can only be applied to large cranes. Considering the chassis layout and cost requirements of small cranes, a new type of operator's cab pitch control system is proposed, which can realize the operator's cab pitch function for small tonnage cranes without increasing the auxiliary pump 1a and reducing the cost investment. Example

[0031] This embodiment provides a novel control room pitch control system, such as... Figure 2 The system includes: a pilot unit, a control room pitch control valve 3, and a control room pitch cylinder 5. The pilot unit includes a pilot pump 1 and a pilot valve 2. The control room pitch control valve 3 is connected in series in the oil circuit between the pilot pump 1 and the pilot valve 2. The control room pitch cylinder 5 is connected to the control room pitch control valve 3. The control room pitch control valve 3 is a three-position four-way solenoid valve with three valve positions and an inlet P, a return port T, a first outlet A, and a second outlet B.

[0032] The first oil outlet A and the second oil outlet B are connected to the rod chamber and rodless chamber of the control room pitch cylinder 5 respectively through the control room pitch balance valve 4, and are used to control the extension and retraction of the control room pitch cylinder 5 to realize the control room pitch function.

[0033] Optionally, the oil outlet of the pilot pump 1 is connected to the oil inlet P of the pitch control valve 3 in the control room, and the oil inlet of the pilot pump 1 is connected to the oil tank.

[0034] The inlet of pilot valve 2 is connected to the return port T of pitch control valve 3 in the control room.

[0035] In this embodiment, the pilot unit provides pilot pressure to the entire vehicle and supplies oil to the control cab for pitching. The control cab pitch control valve 3 is connected in series in the pilot oil circuit. By switching the pilot oil supply to the control cab pitch cylinder 5, the extension and retraction of the control cab pitch cylinder 5 can be realized. The control cab pitch function can be realized without adding an auxiliary pump. In order to prevent the control cab from falling automatically, a control cab pitch balance valve 4 is added, thereby stabilizing the control cab pitch cylinder 5 and playing a balancing and buffering role.

[0036] Optionally, an overflow valve is provided at the oil inlet P of the control room pitch control valve 3. The oil inlet of the overflow valve is connected to the oil outlet of the pilot pump 1, and the oil outlet of the overflow valve is connected to the oil inlet of the pilot valve 2 and the oil return port of the control room pitch control valve 3.

[0037] This embodiment stabilizes the pressure of the pitch cylinder 5 in the control room using an overflow valve, while simultaneously improving the control accuracy and response speed of the pitch in the control room, thus enhancing the overall performance of the equipment. Compared to existing control room pitch designs that utilize an air-filled inflatable concept, this design offers advantages such as lower cost and faster response.

[0038] Optionally, the control terminal of the operator's cab pitch control valve 3 is electrically connected to the controller to switch the position of the operator's cab pitch control valve 3. In this embodiment, the control terminal of the control valve includes a first control interface Y1 and a second control interface Y2. When the first control interface Y1 is energized, the valve core of the operator's cab pitch control valve 3 is adjusted to the left position. When the second control interface Y2 is energized, the valve core of the operator's cab pitch control valve 3 is adjusted to the right position. When neither the first control interface Y1 nor the second control interface Y2 is energized, the operator's cab pitch control valve 3 is in the neutral position, and the hydraulic oil is directly connected to the pilot valve 2 through the neutral position for pilot operation.

[0039] Optionally, the control room pitch control valve 3 has three valve positions, including left, middle and right positions;

[0040] When the control room pitch control valve 3 is in the neutral position, the control room pitch control valve 3 is not connected to the control room pitch cylinder 5;

[0041] When the control room pitch control valve 3 is in the right position, the B port of the control room pitch control valve 3 supplies oil to the rodless chamber of the control room pitch cylinder 5 through the control room pitch balance valve 4, causing the control room pitch cylinder 5 to extend.

[0042] When the control room pitch control valve 3 is in the left position, the A port of the control room pitch control valve 3 supplies oil to the rod chamber of the control room pitch cylinder 5 through the control room pitch balance valve 4, causing the control room pitch cylinder 5 to retract.

[0043] This embodiment replaces the auxiliary valve with a pitch control valve 3 in the operator's cab, offering advantages such as small size and precise control. Employing a three-position five-way directional valve structure, and through optimized internal flow channels and a compact layout, it achieves complex control functions within a limited space. Its size advantage stems from customized design for specific operating conditions, whereas auxiliary valves typically have a single function and require additional installation to perform auxiliary functions, resulting in a larger overall footprint. Therefore, this embodiment achieves precise pitch control of the operator's cab without excessively occupying chassis layout space.

[0044] Optionally, the control room pitch balance valve 4 includes a balance valve pilot port, a balance valve first oil inlet V1, and a balance valve second oil inlet V2.

[0045] The pilot port of the balance valve is set at the first oil inlet V1 of the balance valve and the rod chamber oil port of the pitch cylinder 5 of the control room through the pilot oil circuit, and the first oil inlet V1 of the balance valve is connected to the first oil outlet A of the pitch control valve 3 of the control room.

[0046] The second inlet V2 of the balance valve is connected to the rodless chamber port C2 of the pitch cylinder 5 in the control room, and the second inlet V2 of the balance valve is connected to the second outlet B of the pitch control valve 3 in the control room. The second inlet V2 of the balance valve includes a check valve and a pilot-operated sequence valve. When oil enters through the second inlet V2, hydraulic oil enters through the check valve and returns through the first inlet V1. When oil enters through the first inlet V1, the hydraulic oil acts as pilot pressure to open the pilot sequence valve and returns through the pilot sequence valve.

[0047] Optionally, an overflow valve is installed on the oil line of the P port of the control room pitch control valve 3; the overflow valve needs to match the maximum pitch pressure of the control room and the pressure of the pilot control valve so that the pressure does not exceed the maximum pressure that the gear pump can withstand while the control room can pitch normally.

[0048] Working principle:

[0049] When the driver does not control the pitch of the control room, the controller does not output an electrical signal to the pitch control valve 3. The pitch control valve 3 is in the neutral position, and the hydraulic oil is directly connected to the pilot valve 2 through the neutral position to supply the pilot operation.

[0050] When the driver controls the cab to start, the controller outputs current to the cab pitch control valve 3, the first control interface Y1 of the cab pitch control valve 3 is energized, so that the cab pitch control valve 3 is in the left position. The hydraulic oil enters the second inlet V2 of the balance valve through the second outlet B of the cab pitch control valve 3, and then enters the rodless chamber of the cab pitch cylinder 5. The cab pitch cylinder 5 extends and drives the cab to rise.

[0051] When the driver controls the cab to drop, the controller outputs current to the cab pitch control valve 3, energizing the first control interface Y2 of the cab pitch control valve 3, causing the cab pitch control valve 3 to operate in the right position. Hydraulic oil enters the first inlet V1 of the balance valve through the first outlet A of the cab pitch control valve 3, and then enters the rod chamber of the cab pitch cylinder 5. The cab pitch cylinder 5 retracts, driving the cab to drop.

[0052] In addition, during the raising and lowering of the control room, if the pressure in the control room pitch cylinder 5 is too high, the hydraulic oil will be depressurized to the pilot control valve through the relief valve, which can release excess energy, prevent pressure shock from damaging the system, and at the same time reduce the vibration and noise of the system to improve the user's driving experience. Example

[0053] This embodiment provides a wheeled crane equipped with the aforementioned control system, which is based on the technical concept of Embodiment 1. The wheeled crane in this embodiment is a small-tonnage vehicle. Through the aforementioned control system, without adding auxiliary valves or altering the chassis layout, the pitch function of the small-tonnage wheeled crane can be achieved via the operator's cab pitch control valve on the pilot unit's hydraulic circuit and the operator's cab pitch cylinder connected to the valve. The structure is compact and the control is precise.

[0054] In summary, this invention features a pilot unit hydraulic circuit with a cab pitch control valve and a cab pitch cylinder connected to it. The pilot unit provides pilot pressure to the entire vehicle and simultaneously supplies hydraulic oil to the cab for pitch control. The cab pitch control valve is connected in series in the pilot hydraulic circuit. By switching the pilot oil supply to the cab pitch cylinder, the extension and retraction of the cab pitch cylinder are achieved. This enables the cab pitch function without adding an auxiliary pump. To prevent the cab from falling automatically, a cab pitch balance valve is added, thereby stabilizing the cab pitch cylinder and providing balance and buffering.

[0055] To prevent excessive pressure in the pitch cylinder of the control room, an overflow valve is installed at the pressure port of the pitch control valve in the control room. This valve can stabilize the pressure in the pitch cylinder of the control room and also help improve the pitch control accuracy and response speed of the control room, thereby improving the overall performance of the equipment.

[0056] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0057] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

Claims

1. A novel cab tilt control system characterized by, include: Pilot unit, control room pitch control valve installed on the pilot unit oil circuit, and control room pitch cylinder connected to control room pitch control valve; The pitch control valve in the control room is a three-position four-way solenoid valve with three valve positions and an oil inlet, an oil return port, a first oil outlet, and a second oil outlet. The first oil outlet and the second oil outlet are connected to the rod chamber and rodless chamber of the control room pitch cylinder respectively through the control room pitch balance valve, and are used to control the extension and retraction of the control room pitch cylinder to realize the control room pitch function.

2. The novel control room tilt control system according to claim 1, characterized in that, The pilot unit includes a pilot pump and a pilot valve; the oil outlet of the pilot pump is connected to the oil inlet of the pitch control valve in the control room, and the oil inlet of the pilot pump is connected to the oil tank. The inlet of the pilot valve is connected to the return port of the pitch control valve in the control room.

3. The novel control room tilt control system of claim 1, wherein, An overflow valve is provided at the oil inlet of the control room pitch control valve. The oil inlet of the overflow valve is connected to the oil outlet of the pilot pump, and the oil outlet of the overflow valve is connected to the oil inlet of the pilot valve and the oil return port of the control room pitch control valve.

4. The novel control room tilt control system of claim 1, wherein, The control terminal of the operator's cab pitch control valve is electrically connected to the controller and is used to switch the position of the operator's cab pitch control valve.

5. The novel control room tilt control system according to claim 1, characterized in that, The pitch control valve in the control room has three positions: left, middle, and right. When the control room pitch control valve is in the neutral position, the control room pitch control valve is not connected to the control room pitch cylinder; When the control room pitch control valve is in the right position, oil is supplied to the rodless chamber of the control room pitch cylinder through the control room pitch balance valve at port B, causing the control room pitch cylinder to extend. When the control room pitch control valve is in the left position, oil is supplied to the rod chamber of the control room pitch cylinder through the control room pitch balance valve at port A, causing the control room pitch cylinder to retract.

6. The novel control room tilt control system according to claim 1, characterized in that, The control room pitch balance valve includes a balance valve pilot port, a balance valve first oil inlet port, and a balance valve second oil inlet port. The pilot port of the balance valve is set at the first oil inlet of the balance valve and the rod chamber oil port of the control room pitch cylinder through the pilot oil circuit, and the first oil inlet of the balance valve is connected to the first oil outlet of the control room pitch control valve. The second oil inlet of the balance valve is connected to the rodless chamber oil port of the pitch cylinder of the control room, and the second oil inlet of the balance valve is connected to the second oil outlet of the pitch control valve of the control room. The second oil inlet of the balance valve includes a check valve and a pilot-operated sequence valve. When oil enters through the second oil inlet, hydraulic oil enters through the check valve and returns through the first oil inlet. When oil enters through the first oil inlet, the hydraulic oil acts as a pilot pressure to open the pilot sequence valve, and returns through the pilot sequence valve.

7. The novel control room tilt control system according to claim 1, characterized in that, An overflow valve is installed on the oil line of the P port of the control room pitch control valve. The relief valve is used to limit the maximum pitch pressure in the control room and the pressure of the pilot control valve.

8. A wheel crane, characterized in that The wheeled crane is equipped with a control system as described in any one of claims 1-7.

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