Double-cone-ring synchronous gear shifting mechanism and 3T forklift gearbox gear shifting mechanism

Abstract

The double-cone-ring synchronous gear shifting mechanism comprises a main shaft, a first combination gear, a synchronizer and a second combination gear, a synchronous ring is a double-cone synchronous ring and comprises an inner ring, a middle ring and an outer ring which are sequentially connected in a sleeved mode from inside to outside, a first carbon fiber layer is arranged on the first outer conical surface of the inner ring, and a second carbon fiber layer is arranged on the second outer conical surface of the inner ring. Three radial teeth are arranged on the inner side surface of the inner ring and are clamped on a clutch driven plate hub; a second carbon fiber layer is arranged on the first inner conical surface of the outer ring; three axial teeth are arranged on the end face of the large end of the middle ring, and the axial teeth are inserted into corresponding round holes of the first combination gear or the second combination gear. Existing single-conical-surface friction is changed into double-conical-surface friction, and the carbon fiber layers are arranged on the double conical surfaces, so that the gear shifting force is reduced by 50%, and gear shifting is smoother and more labor-saving; the inner ring and the outer ring are made of iron-based powder metallurgy die castings, the assembly size is not changed, and the cost for replacing an existing 3T forklift with a double-cone synchronous gear shifting mechanism is effectively controlled.

Description

Technical Field

[0001] The invention relates to the technical field of gearbox shifting mechanisms, and in particular to a double-cone ring synchronous shifting mechanism and a 3T forklift gearbox shifting mechanism. Background Art

[0002] The 3T forklift mechanical gearbox widely used in the market is a single cone synchronous ring synchronizer shift gearbox. This gearbox has the advantages of mature technology, economical and reliable, but the disadvantage is that the shift operation is a bit heavy and the driver's labor intensity is high. With the development of society, people pay more and more attention to the comfort of the driver. The original single cone synchronous ring synchronizer shift gearbox is a bit heavy to operate, and the automatic hydraulic forklift gearbox is easy and convenient to operate, but the price is high and uneconomical. The majority of forklift users hope to have an economical and reliable forklift mechanical gearbox with easy shift operation. Summary of the invention

[0003] In order to solve the problem that the operation of the existing 3T forklift mechanical single-cone synchronous ring synchronizer shift gearbox is a bit heavy and the labor intensity of the driver is high, the present invention provides a double-cone ring synchronous shift mechanism, which changes the existing single-cone surface friction into double-cone surface friction, thereby improving the friction torque of the cone surface during shifting and reducing the shifting force of the driver. The existing copper alloy synchronizer ring is changed to a carbon fiber layer provided on the cone surface. The friction coefficient μ of the existing copper alloy ring is 0.08-0.1, while the friction coefficient μ of the carbon fiber is 0.11-0.13, thereby further improving the friction torque of the cone surface during shifting. According to the synchronizer synchronization capacity calculation formula, it can be concluded that the synchronization capacity of the double-cone ring synchronous shift mechanism of the present patent can be increased by 50%, so that the driver can shift more smoothly during operation and the shifting force is reduced by 50%.

[0004] To achieve the above-mentioned purpose, the present invention provides a double-cone ring synchronous shifting mechanism, comprising a main shaft and a first combined gear, a synchronizer and a second combined gear sleeved on the main shaft from left to right in sequence, the synchronizer comprising a long meshing sleeve, a clutch driven disc hub, a slider and a retaining spring, the long meshing sleeve is provided with a first internal spline, the clutch driven disc hub is fixedly connected to the main shaft, the outer circumferential surface of the clutch driven disc hub is provided with a first external spline, the first external spline is meshed and connected with the first internal spline, a synchronizer ring is sleeved between the first combined gear and the synchronizer, and between the synchronizer and the second combined gear, the outer circumferential surface of the synchronizer ring is provided with a second external spline matched with the first internal spline, the first combined gear or the second combined gear is provided with a third external spline matched with the first internal spline near the long meshing sleeve end, the outer circumferential surface of the clutch driven disc hub is provided with three circumferentially evenly distributed through grooves along the axial direction, The slider is provided with three pieces, which are respectively clamped in three through grooves. A boss is provided in the middle of the outer side surface of the slider, and both sides of the boss are transitioned with the step surface in an arc. A first groove is provided in the middle of the first internal spline teeth of the long meshing sleeve, and the first groove is sleeved with the boss. The clamping spring is provided with two pieces, which are respectively arranged in the annular grooves on the two end surfaces of the clutch driven disc hub, and the outer cylindrical surface of the clamping spring is expanded and tightened on the corresponding inner side surface of the slider; The synchronizer ring is a double-cone synchronizer ring, comprising an inner ring, an intermediate ring and an outer ring which are sequentially sleeved from the inside to the outside, the outer circumferential surface of the inner ring is set as a first outer conical surface, and a first carbon fiber layer of uniform thickness is provided on the first outer conical surface, a through hole is provided in the middle of the inner ring, a layer hole is provided at the large end of the through hole close to the first outer conical surface, and three radial teeth uniformly distributed in a circumference are provided on the inner side surface of the through hole, the double-cone synchronizer ring is sleeved in an annular groove corresponding to the clutch driven disc hub at the small end close to the first outer conical surface, three clip grooves matching the radial teeth are provided on the inner side wall of the annular groove, and the radial teeth are clipped in the clip grooves, so that the inner ring and the synchronizer form a synchronous motion connection; a second external spline is provided on the outer circumferential surface of one end of the outer ring far-long meshing sleeve, and the outer side of one end of the near-long meshing sleeve is set as a cylindrical surface with a smaller diameter, and the inner hole of the outer ring is set as A first inner conical surface, wherein the taper of the first inner conical surface is consistent with the taper of the first outer conical surface, and a second carbon fiber layer with uniform thickness is provided on the first inner conical surface, and slider slots are provided on the outer ring at positions corresponding to the three sliders, and the three sliders are respectively clamped in the three slider slots, so that the outer ring and the synchronizer form a synchronous motion connection; the outer circular surface of the intermediate ring is set as a second outer conical surface with the same taper as the second carbon fiber layer, and the inner hole is set as a second inner conical surface with the same taper as the first carbon fiber layer. Three axial teeth uniformly distributed on the large end surface of the intermediate ring are provided, and circular holes are provided on the first and second combined gears at positions corresponding to the axial teeth, and the axial teeth are inserted into the corresponding circular holes, so that the intermediate ring forms a synchronous motion connection with the corresponding first combined gear or second combined gear; An outer stop is provided on the side end face of the first combined gear or the second combined gear near the double-cone synchronizer ring, and the outer stop is sleeved in the layer hole of the inner ring. After the double-cone synchronizer is meshed with the first combined gear or the second combined gear, the corresponding end face of the inner ring is in contact with the stop end face of the first combined gear or the second combined gear; As a further improvement of the present technology, the taper of the first inner conical surface, the second inner conical surface, the first outer conical surface and the second outer conical surface is set to 6.5-7.5°.

[0005] As a further improvement of the present technology, the thickness of the first carbon fiber layer is consistent with that of the second carbon fiber layer, and both are set to 0.5-0.8 mm.

[0006] As a further improvement of the present technology, the bodies of the inner ring and the outer ring are both made of iron-based powder metallurgy die-castings, the composition of which is Fe=90.2-93.3%, C=0.5-0.8%, Cu=1.5-2.5%, Ni=3.5-4.5%, Mo=1.2-2%, and the material density after die-casting is ≥7.0g / cm 3 , hardness ≥ 300HV, tooth hardness ≥ 320HV; The intermediate ring is made of GCr15 bearing steel with a quenching hardness of 58-63HRC, good comprehensive performance, high and uniform hardness after quenching and tempering, and high wear resistance and fatigue resistance.

[0007] The inner ring and the outer ring are made of iron-based powder metallurgy die-castings. Under the premise of meeting the working performance, the increased cost after changing the single-cone synchronizer ring to a double-cone synchronizer ring is reduced, and the increased cost of the double-cone synchronizer ring is controlled within 100 yuan.

[0008] As a further improvement of the present technology, the small end of the second inner conical surface of the intermediate ring is provided with a coaxial inner cylindrical surface extending outward, and the length of the inner cylindrical surface is set to 1±0.1mm; the large end of the second outer conical surface is provided with a coaxial outer cylindrical surface extending outward, and the length of the outer cylindrical surface is set to 1±0.1mm.

[0009] As a further improvement of the present technology, a step surface is also provided on the stop end face of the first combined gear or the second combined gear. After the long meshing sleeve is meshed with the first combined gear or the second combined gear, the gap S between the large end face of the outer ring close to the first inner conical surface and the step surface is set to 1.2±0.2mm, the middle ring end face is flush with the outer ring end face, and at the other end, the outer ring end face extends out of the middle ring end face by L1=0.6~0.8mm, and the middle ring end face extends out of the inner ring end face by L2=1~1.2mm.

[0010] The conical surface of the double-cone synchronizer ring will produce certain wear after long-term use. Therefore, a certain gap (reserve amount) needs to be left between the outer ring and the combined gear (the first combined gear or the second combined gear) so that the conical surface of the double-cone synchronizer ring can continue to be used by adjusting the gap after wear. The setting of L1 and L2 is also to ensure the effective working length of the conical surface after wear, so that the double-cone synchronizer ring can continue to meet the normal working capacity.

[0011] The setting of the reserve amount is not the larger the better, because this reserve amount will cause the long meshing sleeve to form a free flight section before it continues to move forward over the outer ring to mesh with the coupling teeth. If the reserve amount is too large, it is very likely to cause a speed difference between the long meshing sleeve and the coupling teeth again, causing synchronization jamming and difficulty in shifting gears. The reserve amount in the existing synchronous shift mechanism using a single-cone synchronous ring is 1.5±0.2mm. Compared with the prior art, this patent reduces this reserve amount, shortens the free flight section of the long meshing sleeve, and reduces the probability of the long meshing sleeve and the first coupling gear or the second coupling gear generating a speed difference again, thereby achieving no jamming and smoother engagement.

[0012] As a further improvement of the present technology, the meshing angles of the triangular teeth at both ends of the first internal spline are set to 115°±1°, and the middle edge angles of the corresponding triangular teeth are set to 8°±0.5°; the meshing angles and edge angles of the triangular teeth at the end of the second external spline and the third external spline near the long meshing sleeve are consistent with those of the first internal spline.

[0013] The function of the meshing angle is to play a locking role before the long meshing sleeve and the combined gear speed are synchronized (to prevent disengagement: to prevent the long meshing sleeve from meshing with the outer ring and the combined gear before the speed is synchronized), and to mesh with each other smoothly after synchronization. The existing single-cone synchronous shifting mechanism has the situation of disengagement due to the setting of this angle. After calculation, the meshing angle in this patent is set to 115° and the edge angle is set to 8°, which is the best state. It can not only ensure the locking effect and effectively prevent disengagement: prevent the long meshing sleeve from meshing with the outer ring and the combined gear before the speed is synchronized, but also minimize the shifting force.

[0014] As a further improvement of the present technology, the free end of the radial tooth is set to be an arc surface coaxial with the inner ring axis, the radial tooth is set to be a cone with bilateral symmetry and a root width greater than the free end width, and the taper is set to 0.5° to 2°. The setting of the taper makes it easier to assemble the radial tooth and the clutch driven disc hub; The inner side surface of the axial tooth near the axis is set as a conical surface, the taper of the conical surface is consistent with the taper of the second inner conical surface, and both sides of the axial tooth width are set as arc surfaces of the same cylindrical surface. The arrangement of the two sides of the axial tooth on the same cylindrical surface makes it easier to assemble the axial tooth and the combined gear.

[0015] As a further improvement of the present technology, the first combined gear and the second combined gear are both configured as an integrated structure of a transmission gear ring and a third external spline gear ring, a transition cylindrical surface is provided between the transmission gear ring and the third external spline gear ring, a plurality of radial oil inlet holes evenly distributed in a circumference are provided on the transition cylindrical surface, and a slot on the clutch driven hub that matches the radial teeth is configured as a step-shaped slot, and the step-shaped slot passes through the inner side wall of the annular groove on the outer end face side.

[0016] The purpose of this arrangement is to allow the lubricating oil entering from the middle oil inlet hole of the first combined gear or the second combined gear to flow into the synchronizer ring and the clutch driven hub area, so as to lubricate the synchronizer ring, clutch driven hub, slider, long meshing sleeve and other moving parts, thereby increasing the service life.

[0017] The present invention also provides a 3T forklift gearbox shifting mechanism, comprising a main shaft and a high-speed gear, a low-speed gear, a reverse gear gear and a forward gear sequentially sleeved on the main shaft from left to right, the above-mentioned double-cone ring synchronous shifting mechanism is arranged between the high-speed gear and the low-speed gear, and between the reverse gear and the forward gear, and the assembly length of the 3T forklift gearbox shifting mechanism is consistent with that of the existing 3T forklift gearbox single-cone ring synchronous shifting mechanism.

[0018] The purpose of such arrangement is to make the double-cone synchronous shift mechanism compatible with the existing single-cone synchronous shift mechanism, so that the single-cone synchronous shift mechanism on the existing forklift can be directly replaced without replacing the gearbox, thereby reducing the replacement cost of the existing forklift.

[0019] Compared with the prior art, the beneficial effects of the present invention are: 1. The present invention improves the friction force and synchronization capacity of the cone surface during gear shifting by changing the existing single cone surface friction to double cone surface friction, which can transmit greater torque, so that the long meshing sleeve can quickly synchronize the speed with the first combined gear or the second combined gear, and reduces the shifting force of the driver; by arranging a carbon fiber layer on the conical surface of the inner and outer rings of the double cone synchronization, the friction coefficient of the carbon fiber layer is relatively high, which further improves the friction torque and synchronization capacity of the cone surface during gear shifting. According to the calculation formula of the synchronization capacity of the synchronizer, it can be concluded that the synchronization capacity of the double cone ring synchronous shifting mechanism of the present patent can be increased by 50%, so that the driver can shift more smoothly during operation, and the shifting force is reduced by 50%; 2. The inner ring and the outer ring of the present invention are made of iron-based powder metallurgy die castings. Under the premise of meeting the working performance, the additional cost after changing the single-cone synchronizer ring to a double-cone synchronizer ring is reduced, and the additional cost of the double-cone synchronizer ring is controlled within 100 yuan; 3. The ridge angle of the triangular teeth at the inner and outer spline ends of the long meshing sleeve, the outer ring, the first combined gear and the second combined gear that mesh with each other is uniformly set to 8°, and the meshing angle is uniformly set to 115°, which can ensure the locking effect and effectively prevent the gear from being disengaged: prevent the long meshing sleeve from meshing with the outer ring and the combined gear before the speed is synchronized, and minimize the shifting force; 4. The assembly length of the 3T forklift gearbox shifting mechanism of the present invention is consistent with that of the existing 3T forklift gearbox single cone ring synchronous shifting mechanism, so that the double cone synchronous shifting mechanism and the existing single cone synchronous shifting mechanism can be used interchangeably, and the single cone synchronous shifting mechanism on the existing forklift can be directly replaced without replacing the gearbox, thereby reducing the replacement cost of the existing forklift. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a cross-sectional structure of an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a double-cone synchronizer ring according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the outer ring structure of an embodiment of the present invention; Figure 4 for Figure 3 Schematic view of the P-axis spline tooth structure; Figure 5 This is a schematic diagram of the intermediate ring structure in an embodiment of the present invention; Figure 6 This is a schematic diagram of the cross-sectional structure of the intermediate ring in an embodiment of the present invention; Figure 7 This is a schematic diagram of the inner ring structure of an embodiment of the present invention; Figure 8 This is a schematic diagram of the structure of a long meshing sleeve according to an embodiment of the present invention; Fig. 9 for Figure 8 A-axis spline tooth structure view; Fig.10 This is a schematic diagram of the first combined gear structure of an embodiment of the present invention; Fig.11 for Fig.10 The schematic view of the tooth structure in the middle B direction; Fig.12 This is a schematic diagram of the structure of Embodiment 1 of the present invention; Fig.13 The synchronous performance comparison data of Example 1 of the present invention and Comparative Examples 1 and 2 are shown.

[0021] In the figure: 1, first combined gear, 101, third external spline, 102, circular hole, 103, stopper, 104, stop end surface, 105, step surface, 106, transmission tooth, 107, oil inlet hole, 2, double cone synchronous ring, 21, outer ring, 2101, first inner conical surface, 2102, second carbon fiber layer, 2103, second external spline, 2104, slider slot, 22, intermediate ring, 2201, second inner conical surface, 2202, second outer conical surface, 2203, axial tooth, 2204, inner cylindrical surface, 22 05. Outer cylindrical surface, 23. Inner ring, 2301. Through hole, 2302. Layer hole, 2303. First outer conical surface, 2304. First carbon fiber layer, 2305. Radial teeth, 3. Long meshing sleeve, 301. First internal spline, 3011. First groove, 4. Slider, 401. Boss, 5. Clutch driven disc hub, 501. Annular groove, 502. Slot, 6. Second combined gear, 7. Retaining spring, 8. Main shaft, 9. High-speed gear, 10. Low-speed gear, 11. Reverse gear, 12. Forward gear. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] like Figure 1As shown, the embodiment of the present invention includes a main shaft 8 and a first combined gear 1, a synchronizer and a second combined gear 6 which are sequentially sleeved on the main shaft 8 from left to right. The synchronizer includes a long meshing sleeve 3, a clutch driven hub 5, a slider 4 and a retaining spring 7. A first internal spline 301 is provided in the long meshing sleeve 3. The clutch driven hub 5 is fixedly connected to the main shaft 8 through a spline. A first external spline is provided on the outer circumferential surface of the clutch driven hub 5. The first external spline is meshed with the first internal spline 301. A synchronizer ring is sleeved between the first combined gear 1 and the synchronizer and between the synchronizer and the second combined gear 6. A second external spline matching the first internal spline 301 is provided on the outer circumferential surface of the synchronizer ring. The second combined gear 6 of the wheel is provided with a third external spline matched with the first internal spline 301 at the end near the long meshing sleeve 3. The outer circumferential surface of the clutch driven disc hub 5 is provided with three through grooves evenly distributed along the axial direction. The slider 4 is provided with three pieces, which are respectively clamped in the three through grooves. A boss 401 is provided in the middle of the outer side surface of the slider 4. The two sides of the boss 401 are transitioned with the step surface arc. The middle of the first internal spline teeth of the long meshing sleeve 3 is provided with a first groove 3011, and the first groove 3011 is sleeved with the boss 401. The retaining spring 7 is provided with two pieces, which are respectively arranged in the annular grooves 501 on the two end surfaces of the clutch driven disc hub 5. The outer circumferential surface of the retaining spring 7 is tightened on the corresponding inner side surface of the slider 4. like Figure 2 to Figure 7As shown, the synchronizer ring is a double-cone synchronizer ring 2, comprising an inner ring 23, an intermediate ring 22 and an outer ring 21 which are sleeved in sequence from the inside to the outside, the outer surface of the inner ring 23 is set as a first outer conical surface 2303, and a first carbon fiber layer 2304 with uniform thickness is provided on the first outer conical surface 2303, a through hole 2301 is provided in the middle of the inner ring 23, a layer hole 2302 is provided at the large end of the through hole 2301 close to the first outer conical surface 2303, and three circumferential carbon fiber layers are provided on the inner side surface of the through hole 2301 The double cone synchronizer ring 2 is evenly distributed with radial teeth 2305, and the small end of the double cone synchronizer ring 2 is sleeved in the annular groove 501 corresponding to the clutch driven disc hub 5 by the first outer cone surface 2303. The inner side wall of the annular groove 501 is provided with three slots 502 that match the radial teeth 2305. The radial teeth 2305 are clamped in the slots 503, so that the inner ring 23 and the synchronizer form a synchronous motion connection; the outer ring 21 is provided with a second external spline 2103 on the outer circumferential surface of one end of the far-long meshing sleeve 3, and the near-long meshing sleeve 3 is provided with a second external spline 2103. The outer side of one end of the long meshing sleeve 3 is set as a cylindrical surface with a smaller diameter, the inner hole of the outer ring 21 is set as a first inner conical surface 2101, the taper of the first inner conical surface 2101 is consistent with the taper of the first outer conical surface 2303, and a second carbon fiber layer 2102 with uniform thickness is provided on the first inner conical surface 2101, and slider grooves 2104 are provided at positions corresponding to the three sliders 4 on the outer ring 21, and the three sliders 4 are respectively clamped in the three slider grooves 2104, so that the outer ring 21 and the synchronizer form a synchronous motion connection; the outer cylindrical surface of the intermediate ring 22 is set as a second outer conical surface 2202 with the same taper as the second carbon fiber layer 2102, and the inner hole is set as a second inner conical surface 2201 with the same taper as the first carbon fiber layer 2304, and three circumferentially evenly distributed axial teeth 2203 are provided on the large end face of the intermediate ring 22, and circular holes 102 (such as Fig.10 As shown in FIG. 1 ), the axial teeth 2203 are inserted into the corresponding circular holes 102, so that the intermediate ring 22 forms a synchronous motion connection with the corresponding first combined gear 1 or second combined gear 6; like Figure 1 , Fig.10 As shown, an outer stop 103 is provided on the side end face of the first combined gear 1 or the second combined gear 6 near the double-cone synchronizer ring 2, and the outer stop 103 is sleeved in the layer hole 2302 of the inner ring 23. After the double-cone synchronizer 2 is engaged with the first combined gear 1 or the second combined gear 6, the corresponding end face of the inner ring 23 is in contact with the stop end face 104 of the first combined gear 1 or the second combined gear 6.

[0024] Preferably, the taper of the first inner conical surface 2101, the second inner conical surface 2201, the first outer conical surface 2303 and the second outer conical surface 2202 is set to 6.5-7.5°. The taper in this embodiment is 7°.

[0025] Preferably, the thickness of the first carbon fiber layer 2304 is consistent with that of the second carbon fiber layer 2102, and is set to 0.5-0.8 mm. In this embodiment, the thickness is set to 0.52 mm.

[0026] Preferably, the bodies of the inner ring 23 and the outer ring 21 are both made of iron-based powder metallurgy die-castings, the composition of which is Fe=90.2-93.3%, C=0.5-0.8%, Cu=1.5-2.5%, Ni=3.5-4.5%, Mo=1.2-2%, and the material density after die-casting is ≥7.0g / cm 3 , hardness ≥ 300HV, tooth hardness ≥ 320HV; The intermediate ring 22 is made of GCr15 bearing steel with a quenching hardness of 58-63HRC. It has good comprehensive performance, high and uniform hardness after quenching and tempering, and high wear resistance and fatigue resistance.

[0027] The inner ring 23 and the outer ring 21 are made of iron-based powder metallurgy die-castings. Under the premise of meeting the working performance, the increased cost after changing the single-cone synchronizer ring to the double-cone synchronizer ring 2 is reduced, and the increased cost of the double-cone synchronizer ring 2 is controlled within 100 yuan.

[0028] As a preference, Figure 6 As shown, the small end of the second inner conical surface 2201 of the intermediate ring 22 is provided with a coaxial inner cylindrical surface 2204 extending outward, and the length of the inner cylindrical surface 2204 is L4 = 1±0.1mm. The large end of the second outer conical surface 2202 is provided with a coaxial outer cylindrical surface 2205 extending outward, and the length of the outer cylindrical surface 2205 is L5 = 1±0.1mm.

[0029] As a preference, Fig.10 As shown, a step surface 105 is also provided on the stop end surface 104 of the first combined gear 1 or the second combined gear 6, and the step height is 0.3mm. After the long meshing sleeve 3 is meshed with the first combined gear 1 or the second combined gear 6, the gap S between the large end surface of the outer ring 21 close to the first inner conical surface 2101 and the step surface 105 is set to 1.2±0.2mm, and the end surface of the intermediate ring 22 is flush with the end surface of the outer ring 21. At the other end, the end surface of the outer ring 21 extends out of the end surface of the intermediate ring 22 by L1=0.6~0.8mm, and the end surface of the intermediate ring 22 extends out of the end surface of the inner ring 23 by L2=1~1.2mm.

[0030] The conical surface of the double-cone synchronizer ring 2 will produce certain wear after long-term use. Therefore, a certain gap S (as a reserve) needs to be left between the outer ring 21 and the combined gear (the first combined gear 1 or the second combined gear 6) so that the conical surface of the double-cone synchronizer ring 2 can continue to be used by adjusting the gap S after wear. The setting of L1 and L2 is also to ensure the effective working length of the conical surface after wear, so that the double-cone synchronizer ring 2 can continue to meet the normal working capacity.

[0031] The setting of the reserve amount is not the larger the better, because this reserve amount will cause the long meshing sleeve 3 to form a free flight section before it continues to move forward over the outer ring 21 to mesh with the combining teeth. If the reserve amount is too large, it is very likely to cause a speed difference between the long meshing sleeve 3 and the combining teeth again, causing synchronization jamming and difficulty in shifting gears. The reserve amount in the existing synchronous shifting mechanism using a single-cone synchronous ring is 1.5±0.2mm. Compared with the prior art, this patent reduces this reserve amount, shortens the free flight section of the long meshing sleeve 3, and reduces the probability of the long meshing sleeve 3 and the first combining gear 1 or the second combining gear 6 to generate a speed difference again during gear shifting, thereby achieving no jamming and smoother engagement.

[0032] As a preference, Figure 8 , Fig. 9 As shown, the meshing angle α of the triangular teeth at both ends of the first internal spline 301 is 1 All are set to 115°±1°, and the corresponding middle edge angle β of the triangular tooth 1 The meshing angle α of the triangular tooth shape of the second external spline 2103 and the third external spline 101 near the end of the long meshing sleeve 3 is set to 8°±0.5°; 2 , α 3 Both 1 Consistent, and corresponds to the middle edge angle β of the triangular tooth 2 , β 3 Both 1 Consistent.

[0033] The function of the meshing angle is to play a locking role before the speed of the long meshing sleeve 3 and the combined gear (the first combined gear 1 or the second combined gear 6) is synchronized (to prevent disengagement: to prevent the long meshing sleeve 3 from meshing with the outer ring 21 and the combined gear before the speed is synchronized), and to mesh with each other smoothly after synchronization. The existing single-cone synchronous shifting mechanism may be disengaged due to the setting of this angle. After calculation, the meshing angle in this patent is set to 115° and the edge angle is set to 8°, which is the best state. It can not only ensure the locking effect, effectively prevent the long meshing sleeve 3 from meshing with the outer ring 21 and the combined gear before the speed is synchronized, but also minimize the shifting force.

[0034] As a preference, Figure 7 As shown, the free end of the radial tooth 2305 is set to be an arc surface coaxial with the axis of the inner ring 23, and the arc surfaces of the three radial teeth 2305 are on the same circle. The radial teeth 2305 are set to be bilaterally symmetrical and the root width is greater than the free end width. The taper δ is set to 0.5° to 2°. The setting of the taper makes it easier to assemble the radial teeth 2305 and the clutch driven disc hub 5.

[0035] As a preference, Figure 6As shown, the inner side surface of the axial tooth 2203 near the axis is set as a conical surface, the taper of the conical surface is consistent with the taper of the second inner conical surface 2201, and both sides of the tooth width of the axial tooth 2203 are set as arc surfaces of the same cylindrical surface. The arrangement of the two sides of the axial tooth 2203 on the same cylindrical surface makes it easier to assemble the axial tooth 2203 with the combined gear.

[0036] As a preference, Figure 1 , Fig.10 As shown, the first combined gear 1 and the second combined gear 6 are both configured as an integrated structure of the transmission tooth 106 ring gear and the third external spline 101 ring gear, a transition cylindrical surface is provided between the transmission tooth 106 ring gear and the third external spline 101 ring gear, and four radial oil inlet holes 107 evenly distributed in a circumference are provided on the transition cylindrical surface, and the groove 502 on the clutch driven disc hub 5 that matches the radial tooth 2305 is configured as a step-shaped groove, and the step-shaped groove passes through the inner side wall of the annular groove 501 on the outer end face side.

[0037] The purpose of such arrangement is to allow the lubricating oil entering from the middle oil inlet hole 107 of the coupling gear (the first coupling gear 1 or the second coupling gear 6) to flow into the area of ​​the synchronizer ring 2 and the clutch driven hub 5, so as to lubricate the moving parts such as the synchronizer ring 2, the clutch driven hub 5, the long meshing sleeve 3, the slider 4, etc., thereby increasing the service life.

[0038] Embodiment 1 of the present invention is a 3T forklift gearbox shifting mechanism, comprising a main shaft 8 and a high-speed gear 9, a low-speed gear 10, a reverse gear 11 and a forward gear 12 sequentially sleeved on the main shaft 8 from left to right, and a double-cone ring synchronous shifting mechanism of the above embodiment is arranged between the high-speed gear 9 and the low-speed gear 10, and between the reverse gear 11 and the forward gear 12. The assembly length of the 3T forklift gearbox shifting mechanism of this embodiment 1 is consistent with that of the existing 3T forklift gearbox single-cone ring synchronous shifting mechanism.

[0039] The purpose of such arrangement is to make the present embodiment 1 compatible with the single cone ring synchronous shift mechanism of the existing 3T forklift gearbox, and the single cone synchronous shift mechanism on the existing forklift can be directly replaced without replacing the gearbox, thereby reducing the replacement cost of the existing forklift.

[0040] Synchronous performance test: The synchronous performance of this embodiment and comparative examples 1 and 2 when using shifting is tested. Comparative example 1 is an existing 3T forklift gearbox single cone ring shifting mechanism (the synchronous ring is a copper ring), and comparative example 2 is an existing single cone ring shifting mechanism (a carbon fiber layer is provided on the cone surface of the synchronous ring). The test data is shown in Fig.13 As shown in Table 1.

[0041] It can be seen from the synchronization performance data in Table 1 that, compared with comparative example 1, after the single cone ring shift mechanism of comparative example 2 adopts the carbon fiber layer, the cone surface specific pressure is reduced by 19%, and the shift force is reduced by 12%. Compared with comparative example 2, after the double cone rings and the carbon fiber layer are adopted in embodiment 1 of the present invention, the cone surface specific pressure is reduced by 39%, and the shift force is reduced by 44%. Compared with comparative example 1, the cone surface specific pressure, unit sliding friction work, and shift force of embodiment 1 of the present invention are all reduced by more than 50%.

[0042] Fig.13 Table 2 shows the synchronous load-bearing capacity of copper thread and carbon fiber. The data in Table 1 and Table 2 show that the cone surface specific pressure and sliding friction work of the copper thread in Comparative Example 1 exceed its load-bearing capacity, which poses a hidden danger. The use of a carbon fiber layer in Example 1 of the present invention can solve this hidden danger.

[0043] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A double-cone ring synchronous shift mechanism, comprising a main shaft and a first combined gear, a synchronizer and a second combined gear sequentially sleeved on the main shaft from left to right, the synchronizer comprising a long meshing sleeve, a clutch driven disc hub, a sliding block and a retaining spring, the long meshing sleeve is provided with a first internal spline, the clutch driven disc hub is fixedly connected to the main shaft, the outer circumferential surface of the clutch driven disc hub is provided with a first external spline, the first external spline is meshed and connected with the first internal spline, a synchronizer ring is sleeved between the first combined gear and the synchronizer, and between the synchronizer and the second combined gear, the outer circumferential surface of the synchronizer ring is provided with a second external spline matched with the first internal spline, the first combined gear or the second combined gear is provided with a third external spline matched with the first internal spline near the long meshing sleeve end, the outer circumferential surface of the clutch driven disc hub is provided with three through grooves uniformly distributed along the circumference and along the axial direction, The slider is provided with three pieces, which are respectively clamped in three through grooves. A boss is provided in the middle of the outer side surface of the slider, and both sides of the boss are transitioned with the step surface in an arc. A first groove is provided in the middle of the first internal spline teeth of the long meshing sleeve, and the first groove is sleeved with the boss. The clamping spring is provided with two pieces, which are respectively arranged in the annular grooves on the two end surfaces of the clutch driven disc hub, and the outer cylindrical surface of the clamping spring is expanded and tightened on the corresponding inner side surface of the slider; Features: The synchronizer ring is a double-cone synchronizer ring, comprising an inner ring, an intermediate ring and an outer ring which are sequentially sleeved from the inside to the outside, the outer circumferential surface of the inner ring is set as a first outer conical surface, and a first carbon fiber layer of uniform thickness is provided on the first outer conical surface, a through hole is provided in the middle of the inner ring, a layer hole is provided at the large end of the through hole close to the first outer conical surface, and three radial teeth uniformly distributed in a circumference are provided on the inner side surface of the through hole, the double-cone synchronizer ring is sleeved in an annular groove corresponding to the clutch driven disc hub at the small end close to the first outer conical surface, three clip grooves matching the radial teeth are provided on the inner side wall of the annular groove, and the radial teeth are clipped in the clip grooves, so that the inner ring and the synchronizer form a synchronous motion connection; a second external spline is provided on the outer circumferential surface of one end of the outer ring far-long meshing sleeve, and the outer side of one end of the near-long meshing sleeve is set as a cylindrical surface with a smaller diameter, and the inner hole of the outer ring is set as A first inner conical surface, wherein the taper of the first inner conical surface is consistent with the taper of the first outer conical surface, and a second carbon fiber layer with uniform thickness is provided on the first inner conical surface, and slider slots are provided on the outer ring at positions corresponding to the three sliders, and the three sliders are respectively clamped in the three slider slots, so that the outer ring and the synchronizer form a synchronous motion connection; the outer circular surface of the intermediate ring is set as a second outer conical surface with the same taper as the second carbon fiber layer, and the inner hole is set as a second inner conical surface with the same taper as the first carbon fiber layer. Three axial teeth uniformly distributed on the large end surface of the intermediate ring are provided, and circular holes are provided on the first and second combined gears at positions corresponding to the axial teeth, and the axial teeth are inserted into the corresponding circular holes, so that the intermediate ring forms a synchronous motion connection with the corresponding first combined gear or second combined gear; An outer stop is provided on the side end face of the first combined gear or the second combined gear near the double-cone synchronizer ring, and the outer stop is sleeved in the layer hole of the inner ring. After the double-cone synchronizer is engaged with the first combined gear or the second combined gear, the corresponding end face of the inner ring is in contact with the stop end face of the first combined gear or the second combined gear.

2. A double cone ring synchronous shift mechanism according to claim 1, characterized in that: The taper of the first inner conical surface, the second inner conical surface, the first outer conical surface and the second outer conical surface is set to 6.5-7.5°.

3. A double cone ring synchronous shift mechanism according to claim 1, characterized in that: The thickness of the first carbon fiber layer is consistent with that of the second carbon fiber layer, and is both set to 0.5-0.8 mm.

4. A double cone ring synchronous shift mechanism according to claim 1, characterized in that: The bodies of the inner ring and the outer ring are both made of iron-based powder metallurgy die-castings, the composition of which is Fe=90.2-93.3%, C=0.5-0.8%, Cu=1.5-2.5%, Ni=3.5-4.5%, Mo=1.2-2%, and the material density after die-casting is ≥7.0g / cm 3 , hardness ≥ 300HV, tooth hardness ≥ 320HV; The intermediate ring is made of GCr15 bearing steel with a quenching hardness of 58 to 63HRC.

5. The double cone ring synchronous shift mechanism according to claim 1, characterized in that: The small end of the second inner conical surface of the intermediate ring is provided with a coaxial inner cylindrical surface extending outward, and the length of the inner cylindrical surface is set to 1±0.1mm. The large end of the second outer conical surface is provided with a coaxial outer cylindrical surface extending outward, and the length of the outer cylindrical surface is set to 1±0.1mm.

6. A double cone ring synchronous shift mechanism according to claim 5, characterized in that: A step surface is also provided on the stop end face of the first combined gear or the second combined gear. After the long meshing sleeve is meshed with the first combined gear or the second combined gear, the gap S between the large end face of the outer ring close to the first inner conical surface and the step surface is set to 1.2±0.2mm, the middle ring end face is flush with the outer ring end face, and at the other end, the outer ring end face extends out of the middle ring end face by 0.6~0.8mm, and the middle ring end face extends out of the inner ring end face by 1~1.2mm.

7. The double cone ring synchronous shift mechanism according to claim 1, characterized in that: The meshing angles of the triangular teeth at both ends of the first internal spline are set to 115°±1°, and the middle edge angles of the corresponding triangular teeth are set to 8°±0.5°; the meshing angles and edge angles of the triangular teeth at the end of the second external spline and the third external spline near the long meshing sleeve are consistent with those of the first internal spline.

8. The double cone ring synchronous shift mechanism according to claim 1, characterized in that: The free end of the radial tooth is set to be an arc surface coaxial with the inner ring axis, the radial tooth is set to be a cone with bilateral symmetry and a root width greater than the free end width, and the taper is set to 0.5° to 2°; The inner side surface of the axial tooth near the axis is set as a conical surface, the taper of the conical surface is consistent with the taper of the second inner conical surface, and both sides of the tooth width of the axial tooth are set as arc surfaces of the same cylindrical surface.

9. The double cone ring synchronous shift mechanism according to claim 1, characterized in that: The first combined gear and the second combined gear are both configured as an integrated structure of a transmission gear ring and a third external spline gear ring, a transition cylindrical surface is provided between the transmission gear ring and the third external spline gear ring, a plurality of radial oil inlet holes evenly distributed in a circumference are provided on the transition cylindrical surface, and a slot on the clutch driven disc hub that matches the radial teeth is configured as a step-shaped slot, and the step-shaped slot passes through the inner side wall of the annular groove on the outer end face side.

10. A 3T forklift gearbox shift mechanism, characterized in that: It includes a main shaft and a high-speed gear, a low-speed gear, a reverse gear and a forward gear which are sequentially sleeved on the main shaft from left to right. A double-cone ring synchronous shifting mechanism according to any one of claims 1 to 9 is arranged between the high-speed gear and the low-speed gear, and between the reverse gear and the forward gear. The assembly length of the 3T forklift gearbox shifting mechanism is consistent with that of the existing 3T forklift gearbox single-cone ring synchronous shifting mechanism.

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