RU134920U1 - SMALL ELECTRIC LOADER - Google Patents

Abstract

1. A small-sized electric forklift, including a four-wheeled chassis with driving and steered axles, a forklift with a carriage equipped with a fork, a hydraulic drive, an electric drive with electric motors and a pump and a control system that includes a motor controller for the driver, driver’s workstation, steering device, counterweight and a battery, characterized in that the control system is equipped with a pump motor controller, while the motor controller of the movement and the motor controller The pump is designed to reprogram the characteristics of the loader, depending on the installed type of electric motor, forklift, battery, and with the ability to automatically diagnose malfunctions, as well as providing regenerative braking, in addition, the electric forklift contains a pressure sensor that is part of the electric drive and allows the control system control the weight of the load on the forks, an additional counterweight, made in the form of a box for the battery and placed above the steering axle, wherein the primary counterbalance is located at the rear of the housing shassi.2. An electric lift truck according to claim 1, characterized in that it comprises a direct current electric drive. The electric forklift according to claim 1, characterized in that it contains an AC electric drive. The electric forklift according to claim 1, characterized in that the drive axle is mounted on brackets in front of the chassis housing using power pins. The electric forklift according to claim 1, characterized in that the steered axle is attached to the balancer plate of the chassis body. Electric forklift �

Description

The utility model relates to material handling equipment, namely, four-wheel electric forklifts.

Known electric forklift (patent SU 840023 A1 B66F 9/24, publ. 06.23.1981) containing a self-propelled chassis, a forklift with a variable speed load carriage, a movement motor with a control circuit and a hydraulic pump motor with a control circuit. The control circuit of the movement motor includes a controller connected to the pedal, a start contactor and a speed controller, connected in series with the contacts of the start contactor in the power circuit of the movement motor. The control circuit of the hydraulic pump motor includes a starting contactor with a handle for its inclusion, the contacts of which are included in the power circuit of the hydraulic pump motor. The power circuit of the hydraulic pump motor with the contacts of its starting contactor is connected in parallel with the power circuit of the movement motor and in series with the speed controller. The coil of the starting contactor of the hydraulic pump motor is connected to the controller through the handle of its inclusion, and other contacts of the starting contactor of the hydraulic pump motor are included in the coil circuit of the starting contactor of the movement motor.

However, the known electric lift truck has the following disadvantages:

1. Its design does not provide for the possibility of simultaneously performing the functions of the movement of the electric lift truck and lifting the load, which is always necessary when stacking;

2. The connection diagram of electric motors and the coil of the starting contactor in the design of the electric lift truck is archaic and is intended only for contactor control systems. The design of the electric forklift provides ease of use due to electromechanical contactors or relays and is not suitable for installing a modern digital system that would guarantee ease of use by internal logic (electronic program).

The technical task of the utility model is the creation of a compact four-wheel asynchronous electric forklift with a lifting capacity of up to 1.2 tons, having optimal basic working and technical and economic characteristics, and the design of the chassis and hydraulic drive, adapted to work with both AC electrical equipment (asynchronous drive) and with DC electrical equipment, as well as with various types of forklifts and with any of two types of batteries: acidic or alkaline.

The technical problem is solved:

1. The layout and dynamic qualities of the loader, providing the following technical characteristics: absolute indicators:

- rated load capacity - up to 1200 kg;

- full length - up to 2690 mm;

- wheelbase - up to 1055 mm;

- total width - up to 1040 mm;

- height along the fence - up to 2040 mm;

- external turning radius - up to 1645 mm;

- operational weight - up to 2350 kg;

- speed without cargo - up to 16 km / h;

- ground clearance - not less than 125 mm;

- height on the operator’s seat - up to 1004 mm;

- fork lift height (for different types of forklifts) - from 1.55 mm to 4500 mm.

- relative indicators, namely the ratios:

- rated capacity and operational weight of the loader;

- rated load capacity and speed;

- rated load capacity and lifting speeds; - stock stability loader according to GOST 24282:

- longitudinal, when working on a slope of 8.5% (not less).

- transverse, when working on a slope of 8.7% (not less).

These technical specifications listed above provide compactness to the loader and are structurally achieved due to the relatively low center of gravity of the entire loader, as well as the use of a four-support scheme, which together allows to reduce the supporting surface of the entire machine (i.e. track and base).

A low center of gravity is achieved:

- the location of the counterweight in the rear lower part of the housing;

- the use of small diameter wheels on a controlled bridge, which allows a relatively low position of the box with the battery over the controlled bridge.

- the use of bridges (leading and steered), which themselves have a low center of gravity.

- the relatively low location of the hydraulic tank and the pump motor installed in the housing, the installation of the movement motor on the drive axle.

At the same time, the control system:

- providing the most effective operating modes, it allows saving on power characteristics of engines, and therefore on their dimensions;

- provides safe operating modes, previously solved by increasing the dimensions (track and base), which did not allow, for example, to turn the truck over when turning.

2. The presence of one electric drive motor drive (with a rated power of not more than 6 kW) and one hydraulic motor drive (with a rated power of not more than 5 kW).

3. The design of parts and assembly units.

4. The application of the control system for the operation of the electric drive analog (for direct current) or digital (for alternating current), which allows you to automatically select the optimal operating modes, based on the instructions given by the operator and the existing loads on the electric forklift.

5. The use of a digital control system that determines dangerous speeds and prevents the driver from making gross errors, ensuring safety when stacking goods and during movement, and having the ability to reprogram.

6. Installing a pressure measuring sensor in the hydraulic cylinders in the digital control system of the electric forklift, the logic of this system being based, among other things, on diagnosing the load by continuously measuring the weight of the load, movement and lift speeds, engine speed, engine temperature, payload current, degree of discharge of the battery.

7. The possibility of using an alkaline type of battery (battery), as a cheaper and less maintained option than acidic.

8. By placing the counterweight almost at the level of the controlled bridge, as well as placing the battery (battery) in order to perform the function of an additional counterweight (for most loaders, the counterweight is much more massive and heavier).

9. The use of two bridges - steered and driving, which allows us to adopt a four-bearing scheme (four wheels, not three, like most loaders with a lifting capacity of up to 1.2 tons) and, thus, increase the efficiency of the drive axle (the efficiency of the solution with two motors - with wheels - a slightly worse solution with one engine and bridge), as well as improving the stability of the loader when moving and stacking (the stability indices of the four-support scheme significantly exceed the three-support). Also, this scheme allows the design to have a relatively low center of gravity.

10. Universal mounting points (overall and mounting dimensions) for installation on the chassis: motors and control systems, direct or alternating current, forklifts, battery. As well as universal gear ratios of the drive axle, a universal hydraulic system that allows the consumer to select / assemble the product composition at the order stage (cheap option for the consumer) or during operation (on their own - an expensive option for the consumer).

11. The use of a steering mechanism with a simple proximity switch, which provides accurate and reliable mechanical communication between the steering wheel and the metering pump (power steering) with both a direct current and an alternating current drive; placing this mechanism with hydraulic booster - under the floor (under the feet of the operator). In contrast to the common scheme with installing a rudder on the metering pump and placing them above the instrument panel, which leads to the need to “pull” (bring) the high pressure hoses (RVD) to the instrument panel and use a complex universal rotation sensor with corresponding complication of the system operation logic management.

12. The use of an electric travel pedal (“accelerator pedal”) in the chassis, with a potentiometer that can work with either a direct current system or an alternating current system (for most electric forklifts, with a Hall sensor).

13. The use of low-power, and therefore low-cost, electric motors and low weight of the electric forklift, and therefore low - metal consumption.

The technical result of the utility model is to increase the productivity of loading and unloading.

To achieve the specified technical result in an electric forklift, including a four-wheeled chassis with driving and steered axles, a forklift with a carriage equipped with a fork, a hydraulic drive, an electric drive with electric motors for movement and a pump and with a control system including a motor controller for the movement, a driver’s workstation, and a steering device , counterweight and battery, according to a utility model, the control system is equipped with a pump motor controller, while the motor controller the movement shifter and the pump motor controller are configured to reprogram the characteristics of the loader, depending on the type of electric motor, forklift, battery, and with the ability to automatically diagnose malfunctions, as well as providing regenerative braking, in addition, the electric forklift contains a pressure sensor, which is part of the electric drive and allowing the control system to control the weight of the load on the forks, an additional counterweight made in the form of a box for the battery and placed above the steered bridge, with the main counterweight located at the rear of the chassis.

As an electric drive, a direct current or alternating current electric drive can be used.

The drive axle is mounted on brackets in the front of the chassis using power pins.

The steered axle is attached to the chassis chassis balancer plate.

The movement electric motor has a rated power of not more than 6 kW, and the pump electric motor does not exceed 5 kW.

The battery may be acidic or alkaline.

The electric forklift contains a guard for the driver’s workplace, which is a spatial structure welded from a steel profile.

The essence of the utility model is illustrated by drawings.

Figure 1 presents a small electric forklift with a forklift, side view; figure 2 - electric forklift without a forklift, side view; figure 3 - the body of the electric lift truck; figure 4 - drive axle with wheels; figure 5 is a view In figure 4; figure 6 is a left view of figure 4; Fig.7 is a view B of Fig.4; on Fig - presents a controlled bridge with wheels; Fig.9 is a longitudinal section of Fig.8 (fragment); figure 10 shows the placement and appearance of the controls; figure 11 presents the forklift; in Fig.12 is a right side view of Fig.11; in Fig.13 is a top view of Fig.11; on Fig shows the placement and the main composition of the electric drive on a loader; on Fig - view D from Fig; on Fig - view E of Fig; on Fig is a top view of Fig; on Fig - the placement of the elements of the electric drive on the control panel; on Fig - the placement of the elements of the electric drive in the driver's cab; in Fig.20 is a view W from Fig.19; in Fig.21 is a circuit diagram of the electric drive of the loader; in Fig.22 - hydraulic electric lift truck; in Fig.23 shows a steering device; on Fig shows the steering mechanism of the steering device.

The electric lift truck (Fig. 1) contains a four-wheeled chassis 1, a forklift 2 with a carriage equipped with a fork 3, a hydraulic actuator 4, an electric actuator 5.

The chassis of the loader (figure 2) consists of the following parts: body 6 with a driver’s workplace installed on it with a seat, driven 7 and driving 8 axles with wheels, guards 9, controls 10, steering device 11, battery box ( Battery) 12. The chassis of the loader is designed to accommodate components and assemblies, it provides movement and maneuvering the loader. The chassis has universal mounting locations (overall and mounting dimensions) that allow you to install various types of the main parts of the loader, namely the forklift 2, fork 3, hydraulic 4, electric 5 (figure 1).

Driving and steered axles, a forklift, a hydraulic drive, an electric drive, a driver’s workstation and a steering device are mounted on the chassis.

The fence 9 (figure 2) is a spatial structure welded from steel pipes of rectangular cross section. All pipes have the same profile dimensions.

In the box for the battery 12 can be installed, both acidic and alkaline batteries, since the electronic control system of the electric forklift allows you to work with both acidic and alkaline batteries. The box for the battery 12 in addition to its direct purpose serves as an additional counterweight, as it is located in the rear of the chassis 6 - above the controlled bridge 7.

Case 6 (Fig. 3) is a welded supporting structure and contains the following main parts: frame 13, counterweight 14, balancer plate 15, power studs 16, front shield 17, compartment for placing electrical equipment 18 with a door and a lock. Frame 13 consists of sides of transverse and longitudinal ties, brackets and other elements designed to accommodate mechanisms, equipment and assemblies. The counterweight 14 is located in the rear of the housing, which will create a loader design with a low center of gravity and reduce the dimensions of the electric forklift. Power studs 16 are designed to mount the drive axle 8 to the housing 6. The balancer plate 15 is designed to mount the controlled bridge 7.

The driving bridge (Fig. 4) with a movement electric motor, which is part of the electric drive, is mounted on the brackets in front of the housing 6 (Fig. 2) using power pins 16 (Fig. 3). The drive axle (Fig. 4) consists of a single-stage cylindrical gearbox 19 (Fig. 4) with the main gear and differential 20. The movement motor is attached to the gearbox flange 19 with bolts 21. An alternating current (asynchronous) or direct current electric motor can be installed as an electric motor (sequential or mixed excitation). The hubs 22 are mounted on the crankcase 23 of the driving axle on the bearing units 24 and 25 (FIG. 5), as a result of which the axle shafts 26 are unloaded from bending loads. To protect against dust, dirt and leakage of grease, the bearing units 24, 25 are sealed by cups 27 and seals 28. Wheels 30 (figure 4) are attached to the hubs 22 with screws 29 (Fig. 6). To the flanges of the crankcase 31 (Fig.7) of the drive axle, bolts 32 are attached brakes 33 (Fig.6). The brake 33 contains a brake drum 34 (Fig. 7) and a block 35. To prevent an increase in pressure inside the drive axle during operation, a breather 36 (Fig. 6) is installed on the crankcase. A parking brake 37 is attached to the electric motor 17 (Fig. 4).

The controlled bridge (Fig. 8) consists of the following main parts: beams 38, hydraulic cylinder 39, two fists 40 with hubs 41 (Fig. 9). The hubs 41 rotate on bearings 42 and 43. Each hub 41 is fixed to the fist 40 by a nut 44. The earrings 45 (Fig. 8) connect the fists 40 to the rod 46 of the hydraulic cylinder. The hydraulic cylinder 39 is attached to the beam 45 by bolts 47. The fists 40 are mounted in the beam 38 on the pivots 48 (Fig. 9) and bearings 49. The wheels 50 are fixed on the hubs 41 (Fig. 8). The angles of rotation of the wheels 50 are limited by the position of the rod 46. The beam 38 of the steered bridge (Fig. 8) is mounted on bearings 51 and attached to the plate of the balancer 15 of the loader (Fig. 3) with the help of bearing housings 52 (Fig. 8), which makes it possible for the steered bridge swing in the transverse plane.

The use of two bridges - controlled and leading, with a load capacity of 1, 2 tons of electric forklift, allows you to take four-bearing scheme (four wheels) and thus increase the efficiency of the drive axle, as well as improve the stability of the electric forklift when moving and stacking loads. Also, this scheme allows the design to have a relatively low center of gravity.

The main controls (figure 10) include: steering wheel 53; accelerator pedal 54, providing starting and changing the speed; direction indicator switch lever 55; a switch of the direction of movement and inclusion of an audio signal 56; handbrake handle 57 (for DC motor); brake pedal 58; the socket of the power connector 59 to disconnect the battery; a hydraulic actuator control actuation mechanism 60 with tilt handles of the forklift 61 and lift of the forklift 62, which allows for vertical movement of the carriage (with two handles) and control of mounted load-gripping equipment (when two additional handles are installed); control panel 63 with switches for switching on headlights, side lights, switching operating modes (for a loader with an AC motor); indicating device 64. The accelerator pedal 54 can operate both with a direct current electric motor and an alternating current electric motor, since it has a potentiometer.

The design of the inventive electric lift truck has the ability to use various types of forklifts. Presents a forklift is a two-frame telescopic structure (Fig.11-13) and contains a stationary outer frame 65 (Fig.12), a movable inner frame 66 (Fig.13), hydraulic cylinders for lifting the inner frame 67 (Fig.11) and the carriage 68 The outer and inner frames are welded structures of two vertically arranged guides having a special profile, interconnected by transverse bonds. The inner frame moves along the guides of the outer frame on bearings 69 (Fig.13) installed in the profile streams. Two side cylinders for lifting the inner frame are installed in the nests of the lower connection 70 (Fig. 11) of the outer frame. Movable cylinder plungers are mounted on the brackets of the upper link 71 of the inner frame. Along the edges of the upper connection of the forklift are two rollers 73 (Fig. 12) mounted on bearings. Lamellar valuations 74 are thrown through the rollers 73, on which the carriage 68 is suspended (Fig. 11). The second ends of the chains through an adjustable link 75 (Fig. 12) are fixed to the traverse 76. The carriage 68 is used for hanging forks or interchangeable load gripping devices. The carriage 68 moves in the guides of the inner frame on the bearings 77 (Fig.13). Bearings 77 limit lateral displacements of the carriage 68. At the inlet of the working fluid into the hydraulic cylinder, a valve 78 is installed (Fig. 11), which excludes uncontrolled lowering of the load in the event of a break in the working fluid line. The forklift is mounted on a self-propelled chassis of the electric forklift through brackets 79 (Fig. 12) and is held by two tilt cylinders (from the hydraulic drive), through brackets 72 (Fig. 11), which allows you to control its tilt back and forth.

Types of forklifts with forklift may differ from each other by the maximum height of the load, the mass of the forklift and the speed of the load. The smaller the maximum lifting height of the load of the forklift, the less its mass. The main indicator of a forklift is the height of the load. In the declared electric lift truck, any type of forklift with a fork can be used, that is, with any maximum load lifting height: 1.5 m; 1.8 m; 2.3 m; 2.9 m; 3.2 m; 3.3 m; 4,5 m.

The electric drive (Fig.14-21) consists of a control system, engines and additional electrical equipment. The control system consists of programmable controllers operating according to a specific algorithm. The electric drive includes: power connector 80 (Fig.14); control circuit breaker 81; headlight 82; proximity switches 83 (Fig. 15) and 84 (Fig. 16); a battery 85 (FIG. 14); harness 86 (Fig.17); gear pump electric motor 87; tourniquet 88; emergency switch 89; pressure sensor 90; audible warning device 91; oil filter clogging sensor 92; electric motor 93; fuse panel 94 (Fig. 18); pump motor controller 95; motion engine controller 96; the switch of the direction of movement 97 (Fig.19); accelerator 98; microswitch 99, proximity switch 100 (Fig.20).

An electric motor with a power of not more than 6 kW was selected as a movement electric motor, and an electric motor with a power of not more than 5 kW was chosen as a gear pump electric motor. Low-power electric motors have smaller dimensions compared to powerful electric motors, so their use reduces the dimensions of the electric forklift. In addition, the use of low-power electric motors reduces the cost of the electric forklift.

The proximity switches 83 (Fig. 15), 84 (Fig. 16) and 100 (Fig. 20) are made in the form of electric sensors with the effect of "eddy currents", working on the approximation / separation of the metal. They are simple, do not require complex adjustment and layout, do not take up much space. Consume significantly less energy than contact ones.

The pressure sensor 90 measures the pressure of the working fluid in the hydraulic cylinders of the load lifting, and based on this information, the control system, guided by the laid down algorithm, determines the weight of the load, the maximum lifting speed, safe speed of movement. This is a fundamental difference from all known loaders.

Schematic diagram of the electric drive of the loader is presented in Fig.21.

The electric drive ensures the movement of the loader, the operation of the hydraulic system, the operation of sound, light signaling and lighting in accordance with the algorithm of the control system, which allows you to implement the following main functions:

- limitation of work at emergency values of current, speed, voltage, resistance, temperature of the elements of the hydraulic drive and electric drive;

- limiting the extreme high-speed modes of operation of the electric forklift depending on the mass of the transported cargo and the angle of rotation of the steering wheel,

- limitation of extreme high-speed modes of operation of the electric lift truck depending on the mass of the transported cargo and the speed of movement;

- limitation of extreme high-speed modes of operation of the electric forklift depending on the mass of the load and the height of the lift.

The algorithm of the control system includes the following actions:

- the ability to reprogram the characteristics of the loader;

- automatic fault diagnosis and the possibility of regenerative braking;

- the possibility of dynamic (active) electrical braking countercurrent;

- the ability to work with an alkaline type of battery (battery).

The characteristics of the loader, the possibility of reprogramming of which is laid down in the algorithm of the control system, include: speeds and accelerations of movement and lifting of the load; permissible maximum currents when moving and lifting cargo; braking intensity; loader operating time until the battery is completely discharged. All these characteristics depend on the mass of the transported cargo, on the type of battery, on the type of forklift with forklift (forklift trucks differ in the maximum lifting height of the load, i.e. they have different maximum lifting heights and, therefore, different masses of the forklift). These characteristics can be changed when reprogramming the controllers.

Examples:

1) The consumer needs a lifting speed of the load on the forklift with a lifting height of 1.5 m above the standard, at which an increase in currents is required - the control system controllers have the ability to reprogram these parameters.

2) The consumer needs an alkaline type of battery in the electric lift truck, the speeds of which would correspond to the speeds operating on an acid type battery. In this case, the controllers of the control system have the ability to reprogram these parameters.

3) Since the mass of a forklift with a lifting height of 1.5 m is 200 kg less than the mass of a forklift with a lifting height of 4.5 m, reprogramming is performed for efficient operation, that is, the threshold value of the current load is raised and the loader can work with a nominal load of 1, 2 tons instead of 1.0 tons

Reprogramming is carried out through the connection to the controller of a special device - a manual programmer, made to the form of a remote control with a screen on which all program coefficients are visible. By choosing an indicator that is responsible for a certain characteristic and changing its value (for example, from 0 to 1), it is possible to achieve a corresponding change in the operation of the system and the loader as a whole. Reprogramming is achieved by changing the corresponding coefficients in the program (algorithm) of the control system, since the change in these coefficients is caused by changes in physical quantities - current and voltage, with which the controller controls the operation of motors and sensors. For example, you can set the ratio of regenerative braking to dynamic 70/30, while when the gas pedal is released, the controller of the control system gives a command for 70% of the pedal reverse, that is, regenerative braking, and the battery is charged - soft braking occurs, and the remaining 30% of the stroke the controller gives a command for dynamic braking, and the battery is discharged, rotating the engine in the opposite direction to the side - hard braking occurs.

The high-speed characteristics of the loader can also be reprogrammed “manually”, for example, if the task is to transfer the maximum amount of cargo in a very short time without worrying about battery discharge time or about safe modes of operation of the loader.

The possibility of dynamic electric braking in countercurrent, which is inherent in the algorithm of the control system, implies braking when the control system turns on the engine for rotation opposite to the movement, and thereby, while consuming energy from the battery, the loader brakes.

The hydraulic actuator (Fig.22) of the electric forklift is designed to ensure the operation of the steering, lifting devices and interchangeable attachments. The hydraulic actuator comprises a tank 101, a throttle 102, a hydraulic control valve 103, a metering pump 104, a priority valve 105, a gear pump 106, an inlet filter 107, an oil filter 108, an air filter 109, a tilt cylinder 110 and a control pressure pipe 111. All hydraulic drive elements are connected between hoses. The inlet filter 107, the oil filter 108 and the air filter 109 are installed in the tank 101. The control pressure pipe 111 connects the metering pump 104, the priority valve 105 and the wheel turning cylinder 39 (from the controlled bridge). Fill Filter 107 is designed to filter the working fluid poured into the tank during refueling or replenishment. The hydraulic drive allows you to work with both an AC electric drive and a DC electric drive.

The steering device (Fig. 23) comprises a steering wheel 53 fixed by a nut 112 on the splined end of the shaft 113 located in the casing 114, and a steering mechanism 115. A proximity switch 100 is mounted on the steering mechanism 115 by means of bolts 116 and a bar 117, and the lower part of the steering mechanism with bolts 118 attached to the metering pump 104. The steering device 11 (figure 2) is attached to the frame 13 of the housing 6 using a mounting flange (not shown in the figures). The steering mechanism (FIG. 24) is designed to connect the metering pump 104 to the steering wheel 53 (FIG. 23) and provide a signal to the electric drive control system to turn on the pump motor using the proximity switch 100. The proximity switch 100 provides accurate and reliable mechanical steering communication wheels 53 and a metering pump (hydraulic booster) 104 both with a direct current drive and an alternating drive. The steering mechanism (Fig. 24) comprises a housing 121, inside of which a shaft 120 is mounted on bearings 129, connected to the cup 122 by a pin 133 and balls 128. One end of the pin 133 is pressed into the cup 122, and the other is inserted into a longitudinal groove 134 made in the wall shaft 120. A flange 125 is mounted on the upper part of the housing 121. Inside the flange 125, a shaft 119 is mounted on bearings 126, around which a spring 127 is located, one end of which is attached to the cup 122 and the other to the washer 124. The shaft 119 is connected to the spring 127 by a pin 123. Bearings 129 are mounted in two rows, with the lower p the bearing poison 129 is connected to the shaft 119 by a pin 130. A sleeve 131 is connected to the metering pump in the lower part of the shaft 120, and a roller 132 is mounted on the lower end of the shaft 119 for rotating the metering pump shaft 104.

Small-sized electric lift truck operates as follows.

To bring the electric forklift into working condition, it is necessary to supply power from the battery 85 (Fig. 14) to the power connector 80 using the socket 59 (Fig. 10) and turn the key in the switch of the control circuits 81 of the electrical equipment (Fig. 14). In this case, the supply voltage is supplied to the controllers 95, 96 (Fig. 18). The controllers 95 and 96, in accordance with the laid down operational algorithm, begin to “poll” (receive signals) electrical components and if a malfunction is detected, for example, breakage of the harness 88 (Fig. 17), the controller will give an error signal in the form of a corresponding code on the display of the indicator 64 (figure 10). Thus, the control system prohibits further operation of the loader until the cause of the malfunction is eliminated. At the same time, the control system, using the pressure sensor 90 (Fig. 17), controls the weight of the load on the forks and prohibits the lifting of goods with a mass greater than the rated load capacity, and also calculates the degree of discharge from the battery voltage to permit operation with the forklift. In accordance with the mode of operation selected by the operator (driver) of the electric forklift: “Normal”, “Shuttle”, “Economic” by means of a key switch on the control panel 63 (Fig. 10), the control system selects for the motors the corresponding limit characteristics of current, speed, battery voltage etc.

The electric forklift is set in motion by pressing the accelerator pedal 54 (Fig. 10), which feeds the appropriate signals to the controller, while the control system provides smooth acceleration and limitation of the starting currents of the movement motor 93 (Fig. 17) in accordance with the algorithm of the selected operating mode. The movement motor 93 through a single-stage cylindrical gearbox 19 (figure 4). the differential 20 and the half shaft 26 rotates the wheels 30.

Changing the direction of movement is carried out by the lever of the switch of the direction of movement and the inclusion of an audio signal 56 (figure 10), which supplies the corresponding signal to the controllers 95 and 96 (figure 18). When the truck moves in reverse, the reverse lamp (option) automatically turns on and an intermittent sound signal is triggered through the sound signal device 91 (Fig. 17).

When you turn on lifting or tilting the forks using the tilt handles of the forklift 61 and lifting the carriage of the forklift 62 (Fig. 10), as well as when turning the steering wheel 53, the proximity switches 83 (Fig. 15), 84 (Fig. 16), 100 (Fig. .20) generate signals, feed them to the controllers 95 and 96 (Fig. 18), the control system of which includes the electric motor of the pump 87 (Fig. 17) at the required speed. Thus, when the lifting handle of the forklift carriage 62 (FIG. 10) deviates from itself, the supply of working fluid from the tank 101 (FIG. 22) through the metering pump 104 to the priority valve 105 starts. At the same time, the valve spool begins to open through the lifting handle of the forklift carriage 62. 103. In the absence of rudder rotation and, accordingly, the presence of a certain control pressure in the nozzle 111, the priority valve 105 directs the working fluid to the valve spool 103, and then through the open valve 78 (Fig. 11) to the guide avlicheskie cylinders lift the inner frame 67. The valve 78, which plays the role of a constant flow throttle, eliminates the uncontrolled lowering of the load in case of rupture of the hydraulic fluid line. Hydraulic cylinders 67 begin to raise the inner frame by lifting the upper link brackets 71 to the rollers 73. The chains 74 begin to move, and the carriage 68 rises. The lifting speed of the carriage 68 is twice as high as the lifting speed of the inner frame 66. The load is lifting. When the lifting handle of the forklift carriage 62 is set to the neutral position, the signal from the proximity switch 83 to the controllers 95, 96 is stopped, and, by the command of the control system, the pump motor 87 (Fig. 17) is turned off, the spool valve 103 (Fig. 22) is closed, the feed working fluid in the cylinders of the forklift stops, resulting in the load stops. When you deviate from the handle lifting the carriage of the forklift 62 (figure 10), the pump motor does not turn on. The valve spool 103 opens, and the working fluid under the action of the mass of the load and the moving parts of the forklift enters from the hydraulic cylinders of the forklift 67 (Fig.11) through valve 78, the valve 103 and the oil filter 108 (Fig.22) into the tank 101. The load is lowered. The speed of lowering the load is automatically set by the throttle 102.

When the tilt handle of the forklift 61 is rejected (Fig. 10), the proximity switch 84 (Fig. 16) sends a signal to the control system, which includes the electric motor of the gear pump 87 (Fig. 17). The working fluid from the tank 101 (Fig. 22) is supplied through the priority valve 105 to the control valve 103, and then through the open throttle 102 to the rod cavities of the tilt 110 cylinders. The forklift 2 inclines towards itself (Fig. 1). The tilt speed is provided by the control system by turning on the pump motor 87 to the speed required by the operating mode. The working fluid from the piston cavities of the cylinders of the tilt cylinder 110 (Fig. 22) is discharged through the valve 103 and the oil filter 108 into the tank 101. In the event of a clogging of the filter element of the oil filter 108, the clogging sensor 92 (Fig. 17) generates a signal and sends it to the controllers 95, 96. The control system limits the speed of operations and turns on the display device (Fig. 10) on the control panel 63. Returning the tilt handle of the forklift 61 to the neutral position stops the tilt.

When the tilt handle of the forklift 61 deviates from itself, the proximity switch 84 (Fig. 16) sends a signal to the control system, which includes the electric motor of the gear pump 87 (Fig. 17). The working fluid is supplied through the priority valve 105 (Fig. 22) to the control valve 103, and then to the piston cavities of the cylinders of the tilt cylinder 110. The fluid from the rod cavities exits through a small opening of the throttle 102, which slows down the speed of the forklift. When the volume of the working fluid in the tank decreases during operation of the hydraulic actuator, the air filter 109 purifies the atmospheric air entering the tank 101.

The operation of the steering device 11 (figure 2) is as follows. At the initial moment, when the steering wheel 53 is rotated (Fig. 23), rotation through the shaft 113 is transmitted to the shaft 119 (Fig. 24) of the steering mechanism. The shaft 119, using the pin 123, starts to rotate the cup 122. At the same time, the shaft 120 remains stationary due to the great effort to rotate the shaft of the metering pump 104. Since the shaft 120 is stationary, the cup 122 is rotated, is lifted on three balls 128, the edge of the cup is shifted to the center the working end of the proximity switch 100 (Fig.20), which sends a signal to the controller. The control system, based on the speed of movement, the angle of rotation of the steering wheel and the weight of the cargo, determines the amount of fluid needed to rotate the steered wheels 50 (Fig. 8) and includes an electric motor for the gear pump 87 (Fig. 17) at appropriate revolutions. The rotation of the cup 122 (Fig. 24) relative to the shaft 120 occurs until the pin 133, pressed into the cup, abuts against the edge of the oval groove 134 on the shaft 120. The switched-on pump starts supplying the working fluid through the priority valve 105 (Fig. 22) in the metering pump 104, while the force on the rotation of the metering pump shaft drops and the rotation of the shaft begins. In proportion to the angle of rotation of the steering wheel 53 (Fig.23), and hence the shaft of the metering pump 120 (Fig.24), the latter gives a portion of the working fluid to the hydraulic cylinder 39 (Fig.8), responsible for the rotation of the wheels 50. The rotation of the wheels 50 is carried out moving the rod 46 relative to the hydraulic cylinder 39, which rotates the earrings 45, connecting the fists 40 and the wheels 50, at a certain angle, which is limited by the stroke of the rod.

When the rotation of the steering wheel 53 (Fig. 23) is stopped, the spring 127 (Fig. 24) returns the cup 122 to its original position, while the proximity switch 100 (Fig. 20) gives a signal to the controllers 95, 96 (Fig. 18), and, the control system turns off the electric motor of the gear pump 87 (Fig.17). The supply of working fluid to the hydraulic cylinder 39 (Fig. 8) is stopped, and the wheels 50 of the loader (Fig. 8) are fixed in this position.

When the steering wheel 53 is rotated (FIG. 23) in the opposite direction, a similar actuation of the elements of the steering device occurs.

In case of emergency when there is no supply of working fluid to the metering pump, the loader can also be controlled, but the effort on the steering wheel will increase significantly.

In the case of simultaneous operation of the steering device and the control valve 103 (Fig. 22) when the steering wheel 53 is turned, the metering pump 104 issues a certain pressure through the nozzle 111 to the priority valve 105. It switches the priority valve 105, and the working fluid from the gear pump 106 begins to flow into the metering pump 104 from one of the outputs of the valve 105, ensuring the operation of the metering pump 104 in the volume necessary for it. The remainder of the flow rate of the fluid produced by the pump 106 will flow through another valve outlet 105 into the control valve 103. In this case, the speed of the forklift operation will decrease slightly.

The electric forklift is braked by pressing the brake pedal 58 (Fig. 10), while the control system receives and processes the signal from the accelerator 98 (Fig. 19) about braking and does not interfere with it, even when the accelerator pedal 54 is pressed (Fig. 10).

As a parking brake, an electromagnetic brake 37 is used (for an asynchronous drive) (Fig. 4) with spring pressure mounted on the shaft of the motor 93 (Fig. 17).

When the accelerator pedal 54 is pressed, the brake solenoid coil 37 is energized and the motor shaft 93 is released to brake. When the accelerator pedal is released, the control system automatically activates the brake when the loader reaches zero speed (disconnects the power to the electromagnet coil).

To turn off the power in emergency cases, the emergency switch 89 (Fig.17). To make an emergency power outage, you must click on the red head of the rod.

To bring the switch into working condition, pull the rod up by hand.

The inclusion of an audio signal device 91 (Fig.17) is carried out by pressing the button located on the lever of the switch of the direction of movement and enable the audio signal 56 (Fig.10).

Turning on the headlight 82 (Fig. 14) is a switch on the control panel 63 (Fig. 10).

Protection of the electrical circuits of the loader is carried out by fuses installed on the fuse panel 94 in the compartment for placement of electrical equipment 18 (figure 3).

The control system in automatic mode determines the most effective (optimal) modes of operation of the electric forklift,

- based on the characteristics of the main components installed on the loader:

- a forklift, namely its type, mass, friction force;

- battery (battery), namely its type, degree of discharge;

- electric motors, namely their type, operating temperature, number of revolutions);

- based on the instructions given by the operator (driver) and other conditions, for example, cargo weight, rolling resistance.

The most effective operating modes selected with the help of control system controllers provide the highest coefficient of performance (Efficiency) of the main components, which allows to increase work productivity for a given state and modes of operation of the electric forklift.

A change of a certain type of electric motors, a forklift, a battery on an electric forklift is carried out only to perform a certain (expected) work, which must be performed as efficiently as possible. For example - it is necessary “tomorrow” to unload a food container with an unloading height of up to 4.5 m for a limited time. For this type of work, an electric forklift must have: an alkaline battery (non-toxic), since there is work to be done with products, and a forklift with a lifting height of 4.5 m. Therefore, to perform this task, you need to install an alkaline battery and a forklift with a lift height of 4.5 m on the loader. In this case, the characteristics of the loader are reprogrammed, depending on the installed battery type and the installed load type a lift. The control system selects new modes of operation of the loader with an alkaline battery and a forklift with a lift height of 4.5 m. Reprogramming consists of setting (changing) the coefficients in the control program of the controllers so that the system understands which components of the loader it will work with and in what mode (with standard speeds or new). In this case: a forklift with a lift height of 4.5 m has a larger own mass of moving parts that lift the load than a standard forklift with a lift height of 3 m. Therefore, it is necessary to amend the control program for the controllers to process information received from the load weight sensor so that the control system could clearly determine the specific weight of the cargo, and not the total weight of the new moving parts of the forklift and cargo that appeared. Alkaline batteries have a lower operating voltage (40 V instead of 48 V) compared to acid batteries. Therefore, you must also set the battery symptom. The control system, understanding what type of battery it will have to work with, will choose the most effective battery discharge mode for given or new operation speeds. At the same time, it is possible to increase the coefficients responsible for the lifting or moving speeds to change the operating revolutions of the travel engine or hydraulics.

Compared with the closest analogue, the proposed small-sized electric lift truck has a higher productivity when performing loading and unloading operations per unit time, because:

- a control system, the operation of the electric drive, which allows you to automatically select the optimal operating modes, based on the main characteristics of the components, and the operator’s commands and the existing loads on the electric forklift, determine dangerous speeds based on the data received and prevent the driver from making serious mistakes, ensuring safety at stacking of loads and during movement, thanks to the logic (algorithm) of the operation of this system, based on the diagnosis of load by continuous measurement weight of the cargo using a pressure sensor, measuring the speeds of movement and rise, engine speed. At the same time, the logic of the control system prevents dangerous rolls when moving with the load, as a result of which the electric forklift becomes more stable (the operator can completely concentrate on working with the load and not be afraid for safety), which significantly reduces the time, for example, for transferring cargo, and therefore increases the performance of the electric lift truck;

- the ability to reprogram the loader's characteristics control system to the required speed of movement and / or braking, load lifting speed, as well as automatically bring the control system to the most efficient operation of electric motors due to the assessment of the degree of discharge of the battery (battery) by measuring the voltage drop on the battery , engine temperatures, payload currents, cargo weights, respectively, increase the lifespan of the loader;

- the ability to automatically diagnose malfunctions, which allows you to quickly identify and eliminate malfunctions of the loader, and then check its performance, while reducing downtime, which significantly affects the increase in productivity;

- providing regenerative braking, allowing you to charge the battery during the operation, thereby increasing the time of the loader, which also helps to increase the performance of the electric forklift;

- a pressure sensor that measures the pressure of the working fluid in the load lifting hydraulic cylinders, with the help of which the control system controls the load weight, as well as the maximum lift speed, the number of engine revolutions, determines the safe speed of movement and automatically puts the electric motors to the most efficient operating mode, which ensures an increase electric forklift performance;

- placing the main counterweight in the rear of the case, using the battery box together with the battery as an additional counterweight located above the steered axle, allows reducing the dimensions of the electric forklift, reducing its weight and center of gravity, resulting in a compact design, increasing the balance and stability of the loader , and therefore its performance is increased.

Thus, the proposed design of the electric forklift, in comparison with the closest analogue, allows you to perform more work per unit time in accordance with its design features, is more productive.

Claims (9)

1. A small-sized electric forklift, including a four-wheeled chassis with driving and steered axles, a forklift with a carriage equipped with a fork, a hydraulic drive, an electric drive with electric motors and a pump and a control system that includes a motor controller for the driver, driver’s workstation, steering device, counterweight and a battery, characterized in that the control system is equipped with a pump motor controller, while the motor controller of the movement and the motor controller The pump is designed to reprogram the characteristics of the loader, depending on the installed type of electric motor, forklift, battery, and with the ability to automatically diagnose malfunctions, as well as providing regenerative braking, in addition, the electric forklift contains a pressure sensor that is part of the electric drive and allows the control system control the weight of the load on the forks, an additional counterweight, made in the form of a box for the battery and placed above the steering axle, wherein the primary counterbalance is located at the rear of the chassis housing. 2. The electric forklift according to claim 1, characterized in that it contains a direct current electric drive. 3. The electric forklift according to claim 1, characterized in that it contains an AC electric drive. 4. The electric forklift according to claim 1, characterized in that the drive axle is mounted on brackets in front of the chassis using power pins. 5. The electric forklift according to claim 1, characterized in that the steered bridge is attached to the balancer plate of the chassis body. 6. The electric forklift according to claim 1, characterized in that the movement electric motor has a rated power of not more than 6 kW, and the pump electric motor - not more than 5 kW. 7. The electric forklift according to claim 1, characterized in that the battery is acidic. 8. The electric forklift according to claim 1, characterized in that the battery is alkaline. 9. The electric forklift according to claim 1, characterized in that it comprises a guard for the driver’s workplace, which is a spatial structure welded from a steel profile.

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