JPH0318745Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] This invention relates to a transmission.

[Prior Art] In general, in an automobile transmission, in order to quickly and easily change gears while driving, the input shaft and output shaft within the transmission are synchronized so that the gears on the output shaft and the gears on the countershaft mesh with each other. A synchronizer is provided to ensure smooth operation. (Refer to page 65 of Power Transmission Device, Vol. 9, Automotive Engineering Complete Book, published by Sankaido).

However, when shifting up, for example from 1st to 2nd gear, the engine rotation at the time the clutch is released is transmitted to the countershaft as is. In other words, as shown in Figure 5, the rotation on the output shaft side in 1st gear remains transmitted to the countershaft (point P), and as it is, the
When you try to shift up to a higher speed, due to the change in gear ratio, the rotational speed of the countershaft is slower in 2nd gear than in 1st gear relative to the output shaft (point Q), so you need to reduce the rotational speed of the countershaft. In order to achieve a smooth gear change by matching the circumferential speeds of the gear on the countershaft side and the gear on the output shaft side, too much force is applied to the synchronizer.

Therefore, as mentioned above, it is conceivable to provide a brake in the transmission that brakes the countershaft to synchronize the rotational speed of the countershaft with the rotational speed of the output shaft when shifting up from 1st to 2nd speed, for example. .

However, installing a brake inside the transmission requires major modification of the transmission, complicates the shape, increases costs, and makes it difficult to share the transmission case with a transmission that does not have a brake. I can't figure it out. Furthermore, since the brakes are provided within the transmission, it is difficult for the heat generated during braking to escape, making it difficult to cool the brakes.

On the other hand, there is a method such as that disclosed in Japanese Patent Application Laid-Open No. 54-28969. However, since the brake means of this conventional example is attached to the power takeoff (PTO) hole, the heat of the transmission case is directly transmitted to the brake means, and the influence of radiant heat is also large, which is extremely disadvantageous in terms of cooling. When the brake means is installed, there is also the inconvenience that the power take-off device cannot be installed.

[Purpose of the invention] This invention was devised in view of these conventional problems.It does not require major modifications, does not put excessive force on the synchronizer, and is also easy to cool and transport. The purpose of the present invention is to provide a transmission equipped with a countershaft brake with good performance.

[Structure of the invention] To achieve this purpose, this invention includes a case that is supported by the PTO outlet of the transmission case and protrudes from the outer wall of the transmission case, and a countershaft is interlocked with the case within the case. The input side of the power take-off device is provided with a power take-off device in which the rotation shaft on the input side and the power take-off shaft are connected in an intermittent manner, and the power take-off device is provided protruding from the outer wall surface of the case and is interlocked with a countershaft inside the transmission case. The structure is equipped with a brake means that can brake the rotating shaft.

[Embodiment] An embodiment of this invention will be described below in detail based on the drawings.

Figure 1 is an external view of a transmission used in automobiles, etc. On the side of transmission case 1 of this transmission, there is a power take-off device that extracts the power needed for purposes other than driving dump trucks, mixer trucks, etc. That is, a PTO outlet 2 is formed. A gear mounted on a countershaft (countershaft) 3 faces this outlet 2.

FIG. 2 is an enlarged external view of the power extraction device 7 installed at the outlet 2 of the transmission.
The upper flange part 7a in FIG. 2 is brought into contact with the
Fasten with bolts 9. In this installed state, the gear 11 protruding from the top of the power take-off device 7 is always in mesh with the gear 5 on the transmission side.

FIG. 3 is a sectional view of the power take-off device 7, in which the gear 11 is mounted on a shaft 17 rotatably provided to the case 13 via a bearing 15. A gear 19 that meshes with the gear 11 is disposed approximately in the center of the case 13. A shaft portion 19a serving as a rotating shaft on the input side of the power take-off device 11 projects from the left side of the gear 19, and this shaft portion 19a is rotatably supported by the case 13 via a bearing 21. A flange portion 7b formed on the case 13 on the left end side of the shaft portion 19a has a brake means 2 for braking the shaft portion 19a.
3 is attached with bolts 25. Braking the shaft portion 19a means that the gears 19,
Since the countershaft 3 of the transmission which is in an interlocked state is braked via the brakes 11 and 5, the brake means 23 is provided with a braking action for the countershaft 3.

A rotatable power output shaft 29 is interlocked to the right side of the gear 19 via a bearing 27 . Further, on the lower side of the case 13 in FIG. 3, an operating rod 31 that is rotatable with respect to the case 13 is provided. The operating rod 31 inside the case 13 is provided with a gear 1 by moving the power take-off shaft 29 in the left-right direction in the figure.
An actuating piece 33 is attached to connect and disconnect the power take-off shaft 29 and the power take-off shaft 29 .

FIG. 4 is an enlarged sectional view showing details of the brake means 23, in which the left tip of the power take-off shaft 29 extends into the housing 35 of the brake means 23, and a brake plate 37 is provided on the outer periphery of this tip. is rotatably mounted together with the power take-off shaft 29. A moving member 41 that is movable in the left-right direction is disposed within a sliding hole 39 formed in the left-right direction substantially at the center of the left side surface of the housing 35 .

An auxiliary plate 43 is attached to the right end portion 41a of the moving member 41.
are fixed with screws 45. A pad 47 is attached to the right end of the outer circumferential side of the auxiliary plate 43 to abut against the brake plate 37 for braking. In addition, the diaphragm 49 that is in close contact with the left side of the auxiliary plate 43 is
Its outer peripheral end is attached to the inner peripheral wall surface of the housing 35. By providing the diaphragm 49 in this way, the housing 35 and the diaphragm 4
9, a sealed air chamber 51 is formed. This air chamber 51 communicates with an air inflow hole 53 that communicates with an air supply source (not shown). That is, the air supplied from the air supply source flows into the air chamber 51.
When the brake pads are forced inward, the diaphragm 49 receives the pressure, and the pads 47 press against the brake plate 37, thereby performing a braking action.

Next, the operation of the above configuration will be explained.

A countershaft 3 and a gear 5 in a transmission that receive power from an engine (not shown) transmit their rotation to a power output shaft 29 via gears 11 and 19. At this time, for example, if the transmission is in 1st gear, when shifting from 1st to 2nd gear, more specifically, the engine speed is sufficiently increased in 1st gear, the clutch in the transmission is disengaged, and then the gear is shifted to 2nd gear. Immediately before attempting to shift up, the air chamber 51 in Fig.
Air is sent inside and the pad 47 comes into sliding contact with the brake plate 37, thereby decelerating the rotation of the power take-off shaft 29. Along with this deceleration, the change in the gear ratio after the shift-up reduces the amount of deceleration of the rotational speed of the countershaft 3 relative to the rotational speed of the output shaft, and the gears of the output shaft and the gears of the countershaft 3 in 2nd speed are reduced. The meshing is done smoothly.

Note that this invention is not limited to the above-mentioned embodiments. For example, without installing a PTO in the transmission,
Braking means may also be provided on a shaft which is directly driven by a suitable gear on the gear 5 of the countershaft 3.

[Effects of the invention] As described above, according to this invention, since the countershaft can be braked by the brake means during shift up, undue force is not applied to the synchronizer in the transmission case, resulting in a longer life. I can figure it out. Since the brake means is attached to the power take-off device, the brake means can be installed while the power take-off device is attached to the PTO take-off port of the transmission case. Since the brake means brakes the rotating shaft on the input side of the power take-off device, when the device is to be driven by this power take-off device, if the brake means brakes the rotary shaft on the input side of the power take-off device, other Even if the device is driven from a stopped state, the interlocking and disconnection of the input side and output side can be smoothly performed in the power take-off device. In addition, since the brake means is provided protruding from the outer wall surface of the power take-off device, it is not directly transmitted to the brake means of the transmission case, and furthermore, the brake means protruding from the outer wall surface of the power take-off device is extremely advantageous for cooling. be. The brake means can be sub-assembled to the power take-off device, and when the power take-off device is transported alone, the rotating part can be fixed by the brake means, which is extremely advantageous for transportation.

[Brief explanation of the drawing]

The attached drawings relate to an embodiment of the invention, and FIG. 1 is an external view of the transmission showing the installation port of the power take-off device, FIG. 2 is an enlarged external view of the power take-off device compared to FIG. 1, and FIG. The figure is a cross-sectional view of the power take-off device in Figure 2, Figure 4 is a cross-sectional view of the brake means enlarged from Figure 3, and Figure 5 is an explanatory diagram showing the rotational speed of the countershaft at each gear position. . Explanation of the symbols representing the main parts of the drawings: 1...Mission case, 2...PTO outlet, 3...Countershaft (subshaft), 7...Power takeoff device (PTO), 19a...Shaft part ( rotation axis), 23
...Brake means.

Claims (1)

[Scope of utility model registration request] Supported by the PTO outlet of the transmission case,
A case protruding from the outer wall of the transmission case is provided, and within this case is a power take-off device in which an input-side rotating shaft and a power take-off shaft that are interlocked with the countershaft can be connected intermittently. A transmission characterized by being equipped with a braking means that is provided protruding from a wall surface and capable of braking a rotating shaft on the input side of a power take-off device that is interlocked with a countershaft in a transmission case.