SK5093Y1 - Hydraulic maintenance of the tool horizontal, especially the shoveling of the skid steer loader - Google Patents

Abstract

The hydraulic maintenance of the tool horizontal, in particular the shovel alignment of the skid steer loader, resolves the control of the working device consisting of the tool and the tool handling mechanism. It addresses the maintenance of tool horizontality during manipulation. At least one load-independent flow distributor (1) is built into the hydraulic circuit of the working device with the tool handling mechanism control (8) and the tool control (9). This achieves a constant division of the working fluid flow between the straightforward hydraulic motors (5), (6) of the operating device control, which makes it possible to achieve the horizontality of the tool. The priority of the tool section control over the tool self-leveling control allows the at least one logic non-return valve (2) to be integrated into the hydraulic control circuit of the implement. Disabling the tool alignment function during handling will allow the at least one solenoid valve (3) to be included in the hydraulic circuit of the work equipment control.

Description

The technical solution concerns the control of the position of a tool or other part during manipulation, which includes its lifting and lowering. It solves the leveling - the horizontality of the tool by hydraulic control of the working equipment - linear hydraulic motors controlling the tool and the mechanism for manipulating the tool.

Such a tool - a component, is in particular a shovel by a skid steer loader, where the bucket alignment, its horizontality, is solved by hydraulic control of straight-arm hydraulic motors of the boom and bucket during the stroke and lowering of the boom.

BACKGROUND OF THE INVENTION

In handling technology, it is often a requirement to handle a tool or other part that we maintain its constant position - horizontal during handling. An example would be the handling of an open container filled with liquid, with the condition that the container is not tilted during movement. This condition can be met by solving the kinematics of manipulation using the center of gravity of the tool, solving the mechanical connection of the tool position by a system of rods and levers, or by hydraulic control using a balancing valve.

A specific case of tool handling is skid steer loaders, which are used extensively in construction, agriculture, road maintenance, and for transporting and reloading material. For their widespread use, it is very important that these loaders are powerful enough, reliable, easy to maneuver, and recently the requirement for hydraulic bucket positioning has expanded. This is a requirement to hold the bucket in a position so that the bucket contents are not discharged onto the machine cabin when the boom is raised as far as it will go. In the world, skid steer loaders use mainly two types of balancing - bucket positioning, hydraulic and mechanical. Mechanical leveling is provided by a set of levers and drawbars. From the functional point of view, we can divide the hydraulic equalization to equalize the bucket during the boom stroke and to equalize the bucket when lowering the boom. In the world, skid steer loaders are mostly used for easy straightening - only during the boom lift.

The hydraulic connection of the balancing elements using a balancing valve is complicated and energy-intensive, since the flow of working oil from the distributor is throttled.

The pressure oil passes through the ducts and throttles inside the balancing valve, from where it is routed through a duct to the straight-arm hydraulic stroke of the boom, returns to the equalizing valve for further throttling, from there to the straight-arm hydraulic motor, then back to the valve through the distributor into the tank.

The essence of the technical solution

The aforementioned disadvantages of the prior art are eliminated by the hydraulic maintenance of the tool horizontal, in particular the shovel-leveling of the skid steer loader according to the technical solution, wherein the working device consists of a tool and a tool handling mechanism. one distributor with load-independent flow division.

This achieves a constant division of the working fluid flow between linear hydraulic motors of the working equipment control,

In the case of hydraulic buckling of the skid steer loader, this engagement will allow the bucket to be horizontal independently of the load by avoiding cavitation in linear hydraulic motors during negative loading in the boom / boom lift and boom / boom discharge boom / boom.

Depending on the kinematics of the boom with bucket, the constant K should be determined to ensure the necessary bucket alignment mode, specifically for the lift (Ki) and lower (K ₂ ) modes, while maintaining the relationships:

Q ₂ = K,. Q ,,

Qt = K ₂ . Q ₃ , where

Qi - boom stroke flow rate,

Q ₂ - bucket leveling flow during lifting,

Q ₃ - Boom lowering flow.

SK 5093 Υ1

Q ₄ - bucket leveling flow at lowering.

Maintaining the ability to control tool movement in both directions during the lift or lower mode of the tool manipulation mechanism requires the priority of the tool section control over the tool self-leveling control. The functionality of this priority makes it possible to include at least one logic non-return valve in the hydraulic control circuit of the implement.

By inserting at least one solenoid valve into the hydraulic circuit of the operating device, it is possible to disable the tool-compensation function during the lift or lower operation of the tool-handling mechanism. This mode is needed when the bucket is leveled by a skid steer loader to achieve the optimum bucket position to ensure machine stability. Disabling the bucket leveling function is achieved by signals obtained from the position stability sensors or the electronic switch.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in more detail with reference to the accompanying drawings, in which: FIG. 1 shows the principle of flow dividing with application for shovel-controlled shovel loader and FIG. 2 is a diagram of a hydraulic bucket alignment.

EXAMPLES

In FIG. 1 is a diagram of a hydraulic circuit with flow separation by means of a two-section flow distributor (1) with a load-independent flow separation. The first section is controlled by a linear hydraulic actuator of the boom control (5), the second section is operated by a linear hydraulic motor of the bucket control (6). The hydraulic circuit of the example includes a boom control (8) and a bucket control (9).

By connection according to the example, it is possible to achieve a constant flow rate Q ₂ = K, .Q _b when raising the boom and a constant flow rate when lowering the boom

Q4 = K ₂ · ₃ · Q

In the second example of FIG. 2, in the boom control hydraulic circuit of the boom control (5) with bucket operated by the scoop control (6), a logical check valve (2) is included in addition to the load-independent two-section distributor (1). and a solenoid valve (3), both inlet and return.

By connecting according to the example, hydraulic bucket balancing is possible by controlling both sections - for both the boom and bucket with the same control pressure.

Achieving two proportional flow characteristics allows load-independent flow control technology with a constant preset ratio function, even if the maximum possible pump supply is exceeded, while the logic check valve (2) allows bucket control priority to function even during leveling mode.

The solenoid valve (3) allows the bucket alignment mode to be switched off, wherein the solenoid valves (3) are actuated (on and off) by inductive position sensors (not shown in Fig. 2) in boom lift mode to achieve optimum bucket position to maintain machine stability.

Industrial usability

The hydraulic maintenance of the tool horizontal is intended to ensure the horizontality of the various working tools or components during their handling, most often lifting and lowering.

It is designed especially for balancing shovels by skid steer loader.

PROTECTION REQUIREMENTS

Claims (3)

1. Hydraulic maintenance of tool horizontality, in particular shovel-controlled loader shoveling, where the working equipment consists of a tool and a tool-handling mechanism. SK 5093 Υ1, characterized in that at least one switchgear (1) with load-independent flow dividing (1) is built into the hydraulic circuit of the working equipment control. Hydraulic maintenance of tool horizontality, in particular shovel-controlled loader shoveling according to claim 1, characterized in that at least one logic non-return valve (2) is incorporated in the hydraulic circuit of the operating device control. Hydraulic maintenance of tool horizontality, in particular shovel-controlled loader shoveling according to claim 1 and / or 2, characterized in that at least one solenoid valve (3) is incorporated in the hydraulic circuit of the operating device control.