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The TSG 81-2022 issued by the General Administration of China has been officially implemented on December 1, 2022, and the transition period for some projects has reached one year.
Factory vehicles leaving the factory after December 1, 2023 should be equipped with safety monitoring devices in accordance with the requirements of the new regulations.
Today, let's talk about electro-hydraulic commutation, dry goods at the end of the article.
01. Implementation opinions
According to the requirements for the inspection of forklift safety monitoring devices proposed in the new version of the regulations, the General Administration of the People's Republic of China has issued No. 87 document, and considering that the manufacturing unit needs to prepare relevant hardware, software and installation and commissioning work in the actual production process, transitional measures have been proposed for the implementation of the special vehicle safety technical regulations TSG81-2022 in the factory.
To sum it up:
Forklifts that leave the factory after December 1 must be installed with safety monitoring devices in accordance with the requirements of the specification, and they must be covered during inspection.
Forklifts that leave the factory before December 1 also need to be inspected if there is a safety monitoring device.
02. Safety monitoring device
The safety monitoring device mainly includes two major aspects: the driver's sitting and standing posture state perception system and the driver's authority collector. Today, I'm just going to talk about the sitting-standing posture awareness system.
1. Driver's sitting and standing posture perception system
The driver's sitting (standing) posture state perception system is aimed at ride-on electric forklifts, electro-hydraulic reversing ride-on combustion counterbalanced forklifts, and electro-hydraulic reversing ride-on diesel side forklifts.
When the driver is not in the normal operating position, the vehicle can not carry out power operation, even if the load loading and unloading control device is operated, there should be no tilt of the mast and the movement of the fork clamp;
When the driver returns to the normal operating position, but no additional operations are performed, power run, mast tilt and fork movement should not occur automatically.
Note: The attitude perception system is aimed at the forklift, which is first electric or internal combustion electro-hydraulic commutation, which needs to be noted.
In addition, the "power operation" described in the regulations refers to the operation of the forklift body, which can also be simply understood as the forward and backward operation of the vehicle.
The electro-hydraulic commutation in the field vehicle regulations refers to the change of the flow direction of the liquid in the torque converter through the switching of the solenoid valve, so as to realize the change of the running direction of the forklift.
Therefore, electro-hydraulic commutation refers to the conversion of the running direction of the forklift body, such as the switching between forward and backward. It does not refer to the commutation of lifting, descending, tilting and other action mechanisms.
In forklifts, the common transmission modes are: mechanical transmission, hydraulic transmission, hydrostatic transmission, etc.
Mechanical transmission, generally by operating the handle to switch the combination of gears in the gearbox to achieve the effect of reversal.
In hydraulic transmission, there is a torque converter in the general transmission system to connect the output shaft of the engine and the drive axle.
Commonly, in hydraulic transmission, we generally change gears and change the running direction of the forklift by operating the same shift handle as the mechanical transmission.
Electro-hydraulic commutation is to change the flow direction of the liquid in the torque converter through the electric control mode of electricity, through the electric switching of the solenoid valve, instead of manually toggling the gear lever to change the direction of the liquid in the torque converter.
For example, the gear switching of electric vehicles such as Tesla and Xiaopeng Motors also reverses the electro-hydraulic direction through electronic gears.
Electro-hydraulic reversing is a hydraulic control technology, which controls the oil in and out of the reversing valve through the electronic control unit to realize the change of the direction of the machine, which is the product of the combination of hydraulic system and electronic technology.
It can enable the driver to control the solenoid valve in the hydraulic system through the electronic signal on the steering wheel, so as to control the direction of the hydraulic oil flow and realize the reversal of the motor vehicle.
The electro-hydraulic reversing valve is generally a combination of an electromagnetic pilot valve and a hydraulic main valve. For example, the lifting, tilting and other operations of the forklift are realized by pushing buttons, rather than the common manual joystick, which requires special attention. (Here is the author's personal understanding).
In the hydraulic schematic, the symbol looks like this:
The diagonal line represents the hydraulic force and the triangle represents the electromagnetic.