QC/T 1059-2017Truck cabs - Torsion bar tilting and locking mechanisms (English PDF)

3.1 Cab tilting mechanism

The mechanism that allows the cab to be turned over, held in a specific position, and returned to the original position during maintenance of the engine compartment.

3.2 Torsion bar cab tilting mechanism

The cab tilting mechanism taking the torsion bar as the energy storage element; and is divided into single torsion bar cab tilting mechanism and double torsion bar cab tilting mechanism.

4.2 Performance requirements

4.2.1 The locking strength shall meet the following requirements:

--- After testing as per 5.3.1, the safety lock hook shall be free of cracks and deformation;

5.1 Test site

5.1.1 The site for parking the test vehicle shall be horizontal, solid and flat.

5.1.2 The front end of the cab shall reserve sufficient space for tilting.

5.2 Vehicle state

5.2.1 The vehicle state shall meet the technical condition requirements proposed by the manufacturer against such type of vehicle.

5.2.2 Before test, the vehicle shall be stopped stably; while the cab shall remain the exit-factory state.

5.3 Measurement of locking strength

5.3.1 Install the operating mechanism on the test bench; hang the 2000N weight block on the safety lock hook; after standing for 100h, dismantle and measure.

5.3.2 Install the operating mechanism on the test bench; hang the 5000N weight block on the safety lock hook; after standing for 100h, dismantle and measure.

5.4 Operating force for tilting and resetting

5.4.1 Test instrument and device

Force gauge: range of 500N; accuracy level of ±5%.

5.4.2 Method

5.4.2.1 Measurement for operating force of tilting

After unlocking, slowly raise the cab to a static balance; connect the force gauge to the tilting handle; push the tilting handle through the force gauge slowly and perpendicularly to the handle (tangentially along the center of the rotation) till the cab is tilted to the support position; the maximum value displayed by the force gauge during the tilting process is the operating force of such tilting.

5.4.2.2 Measurement for operating force of resetting

After self-unlocking of the stay bar, slowly fall the cab to a static balance; connect the force gauge to the tilting handle; push the tilting handle through the force gauge slowly and perpendicularly to the handle (tangentially along the center of the rotation) till the cab is tilted to the locking position (hooked by the safety locking hook).

6.1 Exit-factory inspection

6.1.1 The product shall be carried out exit-factory inspection according to the specified items; only after passing the inspection can the product leave the factory or store in the warehouse.

6.1.2 The exit-factory inspection items shall be 4.1.1, 4.1.13.

6.1.3 Randomly take 1~2 sets of products from the same batch to carry out exit-factory inspection; if one of the inspection items is unqualified, then such batch of products shall be judged to be unqualified.

6.2 Type inspection

6.2.1 The type inspection items can refer to Table 1. In one of the following cases, the type inspection shall be carried out:

a) When new products are finalized, or old products are transfer for production;

b) When there are significant changes in the product process, structure or materials that may influence the product performance after the formal production;

c) When production is restored after 1-year shutdown;

d) When the normal production reaches 1 year;

e) When the national quality supervision agency proposes the requirements for the type inspection.

6.2.2 The type inspection shall randomly take sample from the same batch of products that have passed the exit-factory inspection; the sampling quantity is 1 set.

6.2.3 If there is one inspection item result does not meet the requirements of this Standard, then take double samples from such batch of products for reinspection. If there is still an unqualified item in the reinspection results, then such batch of products shall be judged to be unqualified.