CN112248802A

CN112248802A - Vehicle transmission system

Info

Publication number: CN112248802A
Application number: CN202011235283.XA
Authority: CN
Inventors: 陆凤祥; 卢晓政; 常飞龙
Original assignee: Jiangsu Yueda Intelligent Agricultural Equipment Co ltd
Current assignee: Jiangsu Yueda Intelligent Agricultural Equipment Co ltd
Priority date: 2020-11-09
Filing date: 2020-11-09
Publication date: 2021-01-22

Abstract

The invention provides a vehicle transmission system, which comprises an engine, a transmission case, a hydraulic control oil path and wheels, wherein the hydraulic control oil path comprises a clutch, an electromagnetic valve, an oil tank, an overflow valve, a filter, a hydraulic pump and a flow valve; the clutch is connected with an electromagnetic valve, one end of the oil tank and one end of the flow valve are both connected with the electromagnetic valve, the other end of the flow valve is connected with one end of a hydraulic pump, the other end of the hydraulic pump is connected with one end of a filter, and the other end of the filter is connected with the oil tank; one end of the overflow valve is connected with the other end of the flow valve, and the other end of the overflow valve is connected with an oil tank.

Description

Vehicle transmission system

Technical Field

The invention relates to the technical field of mechanical control, in particular to a vehicle transmission system.

Background

The high-low gear is a speed change device in a tractor transmission system, and when the traditional mechanical high-low gear structure is used for shifting gears, the power transmitted into a gearbox by the tractor needs to be cut off firstly, so that the operation efficiency is influenced. Meanwhile, when the mechanical high-low gear structure is switched between high and low gears, gear shifting impact is large due to overlarge speed ratio, so that a transmission system gear is damaged, and the service life of the gear is influenced; in the prior art, a scheme of realizing power gear shifting of a high-low gear hydraulic clutch by replacing a high-low gear structure with two axially-arranged multi-plate wet clutches exists, and due to the fact that good control technology is not well processed, the problems of large gear shifting impact and the like can also occur inevitably due to the switching of a gear transmission line with an overlarge speed ratio.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: in order to solve the problems of low efficiency and large loss of a traditional high-low gear structure during gear shifting, the invention provides a vehicle transmission system to solve the problems.

The technical scheme adopted by the invention for solving the technical problems is as follows: a vehicle transmission system comprises an engine, a transmission case, a hydraulic control oil path and wheels, wherein the hydraulic control oil path comprises a clutch, an electromagnetic valve, an oil tank, an overflow valve, a filter, a hydraulic pump and a flow valve;

the clutch is connected with an electromagnetic valve, one end of the oil tank and one end of the flow valve are both connected with the electromagnetic valve, the other end of the flow valve is connected with one end of a hydraulic pump, the other end of the hydraulic pump is connected with one end of a filter, and the other end of the filter is connected with the oil tank; one end of the overflow valve is connected with the other end of the flow valve, and the other end of the overflow valve is connected with an oil tank.

Preferably, the device further comprises a throttle valve and a gear, wherein one end of the throttle valve is connected with one end of the overflow valve, and the other end of the throttle valve is connected with the gear.

Preferably, the clutch further comprises a pressure sensor, and the pressure sensor is arranged between the clutch and the electromagnetic valve in series.

The vehicle transmission system has the advantages that the output torque of the transmission is stable in the power gear shifting process, the electronic throttle of the engine is actively controlled, and meanwhile, the clutches are controlled to be in a whole-course sliding friction state by adjusting and controlling the working pressure of the two clutches.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is a schematic block diagram of a vehicle driveline system according to the present invention.

Fig. 2 is a schematic structural diagram of a hydraulic control oil circuit of a vehicle transmission system according to the present invention.

FIG. 3 is a flow chart of a clutch shift control method of the present invention.

In the figure, 1, a clutch hydraulic cylinder, 2, a pressure sensor, 3, an electromagnetic valve, 4, an oil tank, 5, an overflow valve, 6, a throttle valve, 7, gear lubrication, 8, a filter, 9, a hydraulic pump, 10 and a flow valve.

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 is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", and the like, indicate orientations and positional relationships based on the orientations and positional relationships shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be considered as limiting the present invention.

Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "connected" are to be interpreted broadly, e.g., as being fixed or detachable or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art. In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

As shown in fig. 1-2, the present invention provides a vehicle transmission system, comprising an engine, a transmission case, a hydraulic control oil path and wheels, wherein the hydraulic control oil path comprises a clutch, an electromagnetic valve, an oil tank, an overflow valve, a filter, a hydraulic pump and a flow valve;

each clutch is correspondingly connected with one electromagnetic valve, and the pressure sensors are arranged between the clutches and the electromagnetic valves in series. One end of the oil tank and one end of the flow valve are both connected with the two electromagnetic valves, the other end of the flow valve is connected with one end of a hydraulic pump, the other end of the hydraulic pump is connected with one end of a filter, and the other end of the filter is connected with the oil tank; one end of the overflow valve is connected with the other end of the flow valve, and the other end of the overflow valve is connected with the oil tank.

When the electromagnetic valve is electrified, oil enters the clutch, pushes the piston to move and tightly press a friction plate and a steel sheet of the clutch, and the clutch is engaged. When the electromagnetic valve is powered off, the clutch piston is reset under the action of the return spring, and the oil returns to the oil tank to separate the clutch. In the power gear shifting process, a user actively controls the electronic throttle of the engine, and meanwhile, the working pressure of the two clutches is adjusted and controlled, so that the whole process of the clutches is in a friction state, and the torque output by the transmission is more stable.

In the embodiment, the two clutches are both wet clutches, including the clutch C1 and the clutch C2, the two clutches are respectively and independently controlled, and one wet clutch is in a working state in the same working process; during shifting, one clutch is pressurized and engaged, and the other clutch is released.

According to other embodiments, the device further comprises a throttle valve and a gear, wherein one end of the throttle valve is connected with one end of the overflow valve, and the other end of the throttle valve is connected with the gear. When needed, the oil can be in contact with the gear through the throttle valve, and the gear is lubricated.

Based on the above vehicle transmission system, as shown in fig. 3, the invention also discloses a clutch switching control method, which includes the following steps:

starting at the time S1 and t1, the off-going clutch C1 starts to unload oil, the oil pressure decreases from the maximum value poc to psc, the psc can keep the actual transmission torque Tstart unchanged, and the on-coming clutch C2 starts to charge oil, so that the oil pressure rises from pbase to the oil pressure psb which just overcomes the resistance of the clutch return spring;

at this time, the friction plate clearance of the oncoming clutch C2 is zero, but the pressure acting on the friction plates is 0, and there is no slip between the friction plates, so the transmission torque is also zero;

in the time periods of S2 and t2-t5, the gear shifting process enters a sliding grinding stage; in the slipping phase, the oil pressure of the clutch C1 to be disengaged is reduced according to a certain rule, the oil pressure of the clutch C2 to be engaged is increased according to a certain rule, and the two clutches are in a semi-engaged state independently or simultaneously according to a control strategy; at the moment, the friction plate has relative rotation and sliding abrasion, heat is generated, the rotating speed of an engine, the transmission ratio of a transmission and the output torque are changed rapidly, and the vehicle gear shifting impact is large;

in the time periods of S3 and t5-t6, the gear shifting process enters a new gear maintaining stage; the oncoming clutch C2 is able to transfer all of the torque, and in a fully engaged state, the pressure applied to the oncoming clutch C2 continues to rise to system pressure peb to ensure the ability to transfer maximum torque.

In this embodiment, two clutches have the stage of transmission torque simultaneously, especially when the clutch that shifts rubs, the start-stop scope and the rate of change of two clutch transmission torque that shift have directly influenced the quality of shifting, and reasonable clutch joint law that shifts lets the clutch be in the state that whole journey slided and rubs, has improved the quality of shifting.

According to a further embodiment, step S1 is preceded by the step of: judging the working condition of the vehicle according to the control strategy;

if the vehicle is in a high-load state, a mode of carrying out gear switching with load is adopted;

if the vehicle is in the operating state, the hydraulic shift control system switches between the high and low gears, and the process proceeds to step S1.

In this embodiment, the control strategy is: judging the working condition of the vehicle according to the structural parameters, the operation parameters, the transmission ratio of the engine throttle and the gearbox;

the structural parameters comprise an engine torque equation, vehicle service mass, load distribution coefficient, radius of a driven driving wheel, tire width and vehicle wheel base;

the operation parameters comprise soil specific resistance, load variation coefficient, load frequency domain characteristic, rolling resistance coefficient, gradient, tilling depth and load angle. Two parameters, namely an accelerator and a high-low gear speed ratio, are actively adjusted in the operation process, so that the tractor is ensured to work in a target speed range and a high traction efficiency state.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., 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, a schematic representation of the term does 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.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. A vehicle transmission system is characterized by comprising an engine, a transmission case, a hydraulic control oil way and wheels, wherein the hydraulic control oil way comprises a clutch, an electromagnetic valve, an oil tank, an overflow valve, a filter, a hydraulic pump and a flow valve;

2. A vehicle driveline as recited in claim 1, wherein:

the overflow valve is characterized by further comprising a throttle valve and a gear, wherein one end of the throttle valve is connected with one end of the overflow valve, and the other end of the throttle valve is connected with the gear.

3. A vehicle driveline as recited in claim 1, wherein:

the clutch further comprises a pressure sensor, and the pressure sensor is arranged between the clutch and the electromagnetic valve in series.