JPS597872B2 - pressure control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure control device for controlling hydraulic pressure for operating a hydraulic clutch.

Conventionally, in a hydraulic clutch for connecting/disconnecting or forward/reverse driving force of a marine engine, etc., a hydraulic pump whose pressure increases approximately in proportion to the number of revolutions is used as a hydraulic power source, and this hydraulic pump and the above-mentioned hydraulic clutch are connected. A pressure regulating valve that operates at a predetermined high pressure is installed in the high-pressure oil passage, but whether the marine engine is rotating at low speed or high speed, the pressure regulating valve operates at approximately the same high pressure. Because of this, there is a problem of large power loss during low speed rotation, and
During this low-speed rotation, there was a problem in that a large amount of noise was generated from the reduction gear, reverse gear, etc.

The cause of this noise is that when the above engine rotates at low speed, there is a large torque fluctuation, which causes fluctuations in rotation speed, and the power transmission system after the hydraulic clutch (coupling, propeller shaft, propeller, etc.)
Due to resonance with the inertial mass of the gear, the meshing tooth surfaces of reduction gears, reversing gears, etc. have gaps such as bumps, so the tooth surfaces come into impactful contact with each other, generating large noise.

FIG. 2 shows an example of the above-mentioned conventional pressure regulating valve.
The hydraulic pump a is, for example, a gear pump, which sends pressure oil to a hydraulic clutch (not shown) through a high-pressure oil passage b, and a hole C that communicates with the high-pressure oil passage b has a hole C that is slidable in the axial direction. A spool d is fitted, and the spool d is resiliently pressed by one spring e, and the oil passage b
When the internal pressure rises, the spring e is pressed to the right in the figure, and when a predetermined high pressure P is reached, the pressure oil escapes through the through hole h that communicates with the return oil path g to the tank f. go.

FIG. 1 shows the rotational speed of the gear pump a in this case, that is, the rotational speed N r of the marine engine. p. m. is taken on the horizontal axis, oil path b
The vertical axis is the hydraulic pressure PKy/cr/l of N2500 r. p. m. Hydraulic pressure (P500) at low speed rotation of about
．． p. m. The hydraulic pressure (P2000) at high speed rotation of N-500r. p
．． m. Even at rotational speeds where torque fluctuations are large during low-speed rotation, the hydraulic clutch never enters a so-called half-clutch state, and the fluctuations in rotational speed accompanying torque fluctuations are directly transmitted to the reduction gear, reverse gear, etc., and the gap is reduced. The tooth surfaces of the gears collided with each other, causing a lot of noise.

The present invention has been made with particular attention to the above-mentioned causes of noise, and its purpose is to solve the above-mentioned problems with a simple configuration, reduce noise from reduction gears, reverse gears, etc., and reduce power transmission. The purpose is to extend the life of shafts, etc. and reduce power loss during low speed rotation.

Therefore, a feature of the present invention is that a spool hole is formed in the valve body so as to communicate with a high-pressure oil path connecting a hydraulic pump interlocked with an engine and a hydraulic clutch, and a circulation hole for relief is formed in the spool hole. A spool is fitted inside to be slidable in the axial direction so as to open and close, and a spring is provided to bias the spool toward the high pressure side, so that the spool resists the spring by sensing the pressure in the high pressure oil path. In a pressure control device that slides and releases oil to a circulation hole so that the inside of the high-pressure oil path reaches a predetermined pressure,
The spring is provided with a low-pressure spring and a high-pressure spring, and a throttle oil passage is formed in the subur, and within the sliding range of the spool, the spool slides against the low-pressure spring when the engine rotates at low speed. The low pressure IJ section connects the high pressure oil path with the circulation hole via the throttle oil path, and the spool slides against the high pressure spring when the engine rotates at high speed, connecting the high pressure oil path and the circulation hole. The high pressure IJ and IJ-f sections are provided, and a closed section is provided between these two sections, in which the spool closes the circulation hole.

The present invention will be explained below based on illustrated embodiments.

4 to 6 show an embodiment of the present invention. In FIG. 4, 1 is a marine engine installed in an engine room, and includes an engine body 2, a hydraulic reversing speed reducer 3, and the like.

The reversing speed reducer 3 is composed of a forward hydraulic clutch 4, a reverse hydraulic clutch 5, a forward speed reduction mechanism 6, a reverse speed reduction mechanism 7, etc.
The output shaft 1 of the engine body 2 is connected to the engine body 2 via the hydraulic clutches 4 and 5.
Hydraulic pump 8 such as a gear pump is connected in conjunction with 2.
is attached to the reduction gear 3.

A pressure regulating valve 9 is attached to the high pressure oil passage 13 carrying the hydraulic pump 8 and the hydraulic clutches 4 and 5 through a branched oil passage 14, and the high pressure oil discharged from the hydraulic pump 8 is controlled by the pressure regulating valve 9. The pressure is controlled by a pressure valve 9.

In this way, the pressure regulating valve 9 is interposed in the high-pressure oil passage 13, and the switching valve 10 is further interposed, so that the rotation of the spool 11 selectively controls the hydraulic clutches 4 and 5 from the hydraulic pump 8. High pressure oil is supplied.

It should be noted that the switching valve 10 may optionally have an axially sliding spool.

Therefore, to describe the details of the pressure regulating valve 9, FIG. 4 shows the oil passage 1.
3 and 14 is zero, and its structure is such that a spool hole 16 communicating with the oil passage 14 is bored deep inside the valve body 15 of the case of the hydraulic reversing speed reducer 3. At the same time, a large diameter spring hole 17 is formed at an outer position coaxially with the spool hole 16, and a female threaded portion 18 is formed at the outer peripheral edge of the spring hole 17.

A spool 19 is slidably fitted into the spool hole 16, and a labyrinth groove or the like is provided on the outer peripheral surface 20 to reduce oil leakage from the annular gap with the hole 16, but these grooves are not shown.

A single annular groove 21 is formed on the outer peripheral surface 20, and the annular groove 21 and the inner end surface 22 that communicate with the oil passages 13 and 14 of the spool 19 are connected to the oil passage 2 bored inside the spool 19.
3 is connected.

The reflux hole 24 is perpendicularly opened in the middle of the spool hole 16, and the opening position of the reflux hole 24 is at the annular groove 21 when the pressure is zero as shown in the fourth figure. In order for the annular groove 21 to open into the return hole 24, the spool 19 must slide rightward by a distance A under pressure from the end surface 22.

Reference numeral 25 denotes an oil tank, which is in communication with the return hole 24 through an oil passage 26, and furthermore, an oil passage 27 is connected to the oil passage 26 in order to maintain the pressure inside the spring hole 17 at a low pressure. The oil passage 27 is configured to branch from the middle, and communicates with the spring hole 17 in an open manner through a drain hole 28 .

29 is threadedly connected to the female threaded portion 18 and is connected to the gasket 3.
0 sealed plug.

A small-diameter female screw hole 31 is formed in the axial center of the plug 29, and a pressure regulating bolt 32 is inserted into the screw hole 31 so as to be freely threadable.

Numeral 33 is a lock nut for locking the bolt 32 after it has been screwed into the spring chamber 34 formed by the spring hole 17 and the plug 29 by a predetermined length. It is.

35 is a cap having a blind female screw hole 36;
The space between the lock nut 33 and the gasket 37 is sealed to prevent oil leakage to the outside, and another gasket is also provided between the surfaces of the lock nut 33 and the plug 29 that should come into contact. A sket 38 is interposed to similarly prevent oil leakage.

Further, 39 is a washer, and a small diameter coil spring 40 elastically presses the washer 39.

Then, one end of the coil spring 40 is engaged with the inner end surface 41 of the bolt 32, and the other end is pressed against the washer 39 as described above, and the subur 19 is pulled out through the washer 39 as shown in FIG. suppressed to the left, and with that,
When the pressure increases in the high pressure oil passages 13 and 14 in a relatively low range, only this small diameter spring 40 generates a reaction force.

42 is a large diameter coil spring with a large spring coefficient, and is housed in the spring chamber 34 on the same axis as the small diameter coil spring 40.
The outer diameter of the spring hole 17 is slightly smaller than the inner diameter of the spring hole 17, and one end of the plug 29 contacts the inner end surface of the plug 29, and the other end contacts the washer 39. However, as is clear from FIG. 4, the free length of the coil spring 42 is slightly smaller than the distance between the inner end surface of the plug 29 and the washer 39.
The pressure in the oil passages 13 and 14 rose slightly, causing Subur 19,
It is not until the washer 39 moves to the right in the figure against the small diameter coil spring 40 that the washer 39 and the end face of the large diameter coil spring 42 come into contact as shown in FIG.

That is, when the pressure in the oil passages 13 and 14 is zero, a gap dimension B is provided, and FIG. 5 shows a state in which this gap disappears and the washer 39 and the spring 42 are in elastic contact.

In FIG. 3, the horizontal axis represents the rotational speed Nr, p, m of the hydraulic pump 8.
, and the discharge pressure of hydraulic pump 8, that is, oil passage 1, is measured in the vertical direction.
The pressure PKy/cr/l of 3.14 is taken, but it can be seen that the pressure P increases almost proportionally to the rotation speed N from pressure P = OKy/cl to P = P. As can be seen, the state of the pressure regulating valve 9 at this time is shown in Fig. 4 as shown in Fig. 5. A horizontal portion 43 is shown, which is used to reduce a portion of the oil amount in the oil passage 13 to a low pressure IJ IJ-
When the spool 19 of the pressure regulating valve 9 is in the state shown in FIG. 5, the pressure oil in the oil passages 13 and 14 flows in the direction of arrow C in the figure. are doing.

That is, the annular groove 21 opens into the return hole 24, and the oil passage 2
3, the oil flows in the direction of arrow C, and is relieved from the oil passage 26 to the tank 25.

At this time, the dimension A in FIG. 4 gradually decreases, eventually reaching zero, and then becoming a negative value.

At this time, if (A<B) is set, the above low pressure IJ I
After J-F, the large-diameter coil spring 42 is compressed only when the pressure P increases further, and therefore, the pressure P increases in direct proportion to the rotational speed N, as shown by the inclined straight line 44 in Fig. 3. We will continue to do so.

Note that at this time, the annular groove 21 of the spool 19 is connected to the hole 24.
, so that oil no longer flows into the oil passage 23 again.

As the rotational speed N of the hydraulic pump 8 increases and becomes a high-speed rotation, it finally reaches a predetermined high pressure P0, and as shown in the horizontal portion 45 of FIG. 3, even if the rotational speed N changes. , the pressure P is constant at P1.

This is a high-pressure IJ-off state, and the total amount of oil discharged from the pump 8 is IJ-off.

FIG. 6 shows this high pressure relief state, and as shown by arrow D, the end face 22 of the spool 19 opens into the hole 24 and oil is relieved, and both the small diameter and large diameter coil springs 40 and 42 Largely compressed, spool 19
It elastically resists the pressure acting on the end surface 22 of.

Conversely, when the rotational speed N decreases, the spool 19 sequentially moves in the opposite manner to the above, and returns to the origin by following the curve shown in FIG. 3 in the opposite direction.

In FIG. 3, the rotation speed N1 of the hydraulic pump 8, that is, the rotation speed N of the output shaft of the marine engine 1 is approximately 50 Or. p. m. Up to the vicinity, the pressure P in the oil passage 13 is about P2=3KP/d, and N is 1300 to 1500 r.
p. m. This value is set at approximately P1 = 15Kp/7 for the first time, or the setting of this value is due to the limit pressure at which the hydraulic clutches 4 and 5 become half-clutched, the torque fluctuation of the marine engine 1, and the rotation speed N where the rotational fluctuation is large. Although it can be changed freely depending on the range of
3, and is configured to have a two-stage relief state of low pressure IJ IJ-f and high pressure +) +) 1f.

In addition, in FIG. 3, the conventional case is shown with a broken line to clarify the difference.

Next, FIGS. 7 to 9 show other embodiments of the pressure regulating valve 9, in which FIG. 7 is shown in FIG. 4, FIG. 8 is shown in FIG. 5, and FIG. 9 is shown in FIG. 6 illustrates a state corresponding to the above-mentioned FIG. 6, and flow arrows C and D also indicate states corresponding to each.

The difference from the previous embodiment is that the spool has a two-stage spool structure consisting of a large spool 46 and a small spool 47 that is slidable within the same axis as the dog spool 46.

That is, the small spool 47 is slidably fitted into the through hole 48 of the large spool 46, and a large diameter portion 49 is provided at the right end to prevent it from falling off in the left direction from the through hole 48. , the large diameter portion 49 is elastically biased leftward by a small diameter coil spring 40 to resist the pressure P acting on the end surface 50 of the spool 47.

Reference numeral 51 denotes a pressure regulating plug, which has the same function as the pressure regulating bolt 32.

In other words, the outer peripheral male thread of the plug 51 or the dog spool 4
It is screwed into a female screw part 53 formed from the right end part 52 side of the spring 6, and by screwing it, the elastic force of the spring 40 can be changed, and the same low pressure IJ IJ-fu pressure P2 as described above can be adjusted. .

This small spool 4T is provided with an oil passage 23 and an annular groove 21, as in the previous embodiment.

Next, the large spool 46 is bored coaxially with the through hole 48 into which the small spool 47 is to be inserted, and the female threaded portion 53, etc., and communicates with the oil passage 13 formed in the valve body 15. a small diameter portion 54 that is slidably and tightly fitted into the communicating spool hole 16;
It has a stepped rod-like outer circumferential surface shape consisting of a large diameter portion 55 located at the female threaded portion 53.

A large-diameter coil spring 42 with a large spring coefficient is interposed with a washer 56 at the end 52 on the large-diameter portion 55 side, and elastically biases the large spool 46 in the left direction.

The spring chamber 34 has a large diameter spring 42 in this way.
only is internally possessed.

Further, in the small diameter portion 54, an annular groove 57 is formed on the outer peripheral surface, and an annular groove 58 is formed on the inner peripheral surface of the through hole 48,
These two grooves 57, 58 are communicated with each other by a small radial hole 59.

The reflux hole 24, drain hole 28, etc. are the same as in the previous embodiment.

Further, the relationship between the rotation speed N and the oil pressure P is similarly as shown in FIG.

In other words, as the pressure P increases sequentially from zero to P2, the small spool 47 moves to the right against the through hole 48 of the thick spool 46 against the small diameter coil spring 40, and P
- When it reaches P2, it moves by the dimension A, and the oil passage 23, annular groove 21, annular groove 58, small diameter 59, and annular groove 57 become connected, and the pressure oil flows in the direction of arrow C, resulting in a low pressure relief state. .

At this time, the large diameter coil spring 42 is also compressed, but the end surface 60 does not open into the hole 24 yet.

Furthermore, as the pressure P increases, the spool 46 gradually becomes thicker.
moves to the right against the large diameter coil spring 42, and finally the end face 60 opens into the hole 24 as shown in FIG.
At the pressure P1, the same high pressure IJ-IJ-f state as described above occurs, and the entire amount of pressure oil flows in the direction of arrow D.

Therefore, FIG. 10 shows the rotating shaft 6 shown in FIG. 1 after passing through the output shaft 12 and the hydraulic clutches 4 and 5 during low-speed rotation.
The torque variation TK5f-m of 1.62 is shown.

In a device with a conventional pressure regulating valve, N =
50 O r. p. m. Since the pressure P=P500 is high even during low-speed rotation, which is not different from the pressure P1000 or P2000 during high-speed rotation, the friction clutch plates of the hydraulic clutches 4 and 5 often idle in a half-clutch state. The output shaft 12 and the rotating shaft 61 or 62 always rotate integrally, so that the peak portion 63 of the fluctuating torque is transmitted from the output shaft 12 to the rotating shaft 61 or 6.
In contrast, the pressure control device of the present invention has the above-described structure and operation, so that the N-50
0 to 600 r. p. m. When rotating at low speeds such as
Since P=P2<P1 and low-speed relief pressure is acting on the hydraulic clutch 4 or 5, the friction clutch plate has a constant torque T.

In the above case, the clutch is in a so-called half-clutch state and is idling, so that the peak portion 63 is cut off at the broken line as shown by diagonal lines in FIG. 10, and the power is transmitted to the rotating shaft 61 or 62. Since only a uniform low torque with a small amplitude is transmitted to the transmission system after the cut, the rotating shaft 6
No. 1, 62 and subsequent power transmission systems have a particularly significant improvement in fatigue strength, resulting in an extended service life.

Furthermore, the hydraulic pump 8 is connected and driven to the rotary shaft 62, or the peak portion of torque fluctuation is cut, and the fluctuation amplitude is made small and uniform, and the rotational speed of the rotary shaft 62 is also fluctuated or reduced, and the hydraulic clutch 4, There is no resonance with inertial masses other than 5 (propeller shaft, propeller, etc.), and the tooth surfaces of the reduction gears, reverse gears, etc. of the forward and reverse speed reducers 6 and 7 do not come into impactful contact with each other, resulting in significant noise. Therefore, it is preferable to use it in marine engines and the like.

The pressure control device of the present invention includes a low-pressure spring and a high-pressure spring, and also forms a throttle oil passage in the spool so that the spool resists the low-pressure spring during low-speed rotation of the engine within the sliding range of the spool. A low-pressure IJ-IJ-f section that slides and communicates the high-pressure oil path and the circulation hole via the throttle oil path, and a high-pressure oil path that the spool slides against the high-pressure spring when the engine rotates at high speed. and a high pressure relief section communicating with the circulation hole,
Since there is a closed section between these two sections where the spool closes the circulation hole, the desired purpose as stated at the beginning can be achieved, and therefore, the noise at low speeds from reduction gears, reversing gears, etc. can be significantly reduced. At the same time, it is possible to prevent torsional vibrations in the power transmission system after the hydraulic clutch, and to significantly extend the life of the hydraulic clutch.

Furthermore, power loss due to reduction in oil pressure during low-speed rotation can also be reduced.

In addition, low pressure and high pressure are automatically obtained according to the engine rotation speed, and there is no need for any separate switching valves.The structure is simple, and there is no need to determine the switching timing. It is also extremely easy to handle during operation.

Moreover, when starting the vehicle, if the engine speed is increased from a low speed, the hydraulic clutch first engages at low pressure and then engages at high pressure, making it possible to start smoothly.

[Brief explanation of drawings]

Figure 1 is a graph showing the characteristics of a conventional pressure control device, Figure 2 is a graph showing the characteristics of a conventional pressure control device.
3 is a graph showing the characteristics of the device of the present invention. FIG. 4 is an explanatory diagram and an enlarged sectional view of essential parts showing an embodiment of the present invention. FIGS. The figure is an enlarged sectional view of the same essential part for explaining the operation, FIG. 7 is an enlarged sectional view of the essential part showing another embodiment, FIGS. 8 and 9 are enlarged sectional views of the same essential part for explaining the operation,
FIG. 10 is a graph showing an example of torque fluctuation. 4, 5...Hydraulic clutch, 8...Hydraulic pump, 9...Pressure regulating valve, 13...High pressure oil path, P1... High pressure, P2...Low pressure.

Claims (1)

[Claims] 1 A spool hole is formed in the valve body so as to communicate with the high pressure oil path connecting the hydraulic pump and the hydraulic clutch that are linked to the engine, and a spool hole is formed in the spool hole in the axial direction to open and close the relief circulation hole. A spool is fitted inside the spool so that it can move freely, and a spring is provided that urges the spool toward the high pressure side.The pressure inside the high pressure oil path is sensed and the spool slides against the spring, causing the inside of the high pressure oil path to reach a predetermined pressure. In the pressure control device, the oil is released to the circulation hole as shown in FIG. When the engine rotates at low speed, the spool slides against the low-pressure spring and connects the high-pressure oil passage and the circulation hole through the throttle oil passage. A high-pressure IJ-F section that slides against a high-pressure spring and communicates the high-pressure oil path and the circulation hole is provided, and a closed section in which the spool closes the circulation hole is provided between the two sections. Features a pressure control device.