JPS6153463A - Nozzle device for pelton wheel - Google Patents

Abstract

PURPOSE:To let needle's self-closing force in time of opening drop to some extent as well as to reduce driving force of the needle, by installing a spring, exerting energizing force on the needle in the closing direction, and another spring, exerting the energizing force on the needle in the opening direction only in case of full-close of the needle and the vicinity. CONSTITUTION:When a needle 6 is full-close, a spring 16 built in position between an end part 9a of a cylinder 9 and a piston 12 in a servomotor 7 is made compressed whereby energizing force in an opening direction is given to the needle 6 via an output shaft 8. And, a spring pushing part 6a of the needle 6 is separated from a spring bearing 15, intercepting a spring 14 inside a spring chamber 13 exerting its energizing force on the needle 6. Under this condition, when pressure oil is fed to the inside of the cylinder 9 from a hydraulic port 11, the needle 6 gets opening by degrees. And, when opening of the needle 6 reaches the middle part, hydraulic unbalancing force due to hydraulic pressure and the energizing force of a spring 16 turns round, acting on the opening direction of the needle 6. Therefore, driving force of the servomotor 7 is reducible.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a nozzle device for a Pelton water turbine, and more particularly to a nozzle device in which a hydraulic servo motor for driving a needle is built into a nozzle pipe. .

[Technical background of the invention and its problems]

Figure 1 shows a Bern water turbine using a nozzle device in which a hydraulic servo motor is built into the nozzle pipe.
is arranged to be rotatable about a vertical axis. On the outer periphery of this runner 3, four nozzles 4 are installed at a 90' phase.
The runner 3 is arranged so that a jet of pressurized water is ejected tangentially to the runner 3 to drive the packet 2.

This nozzle 4 has a nozzle pipe 5, as shown in detail in FIG. The servo motor cylinder 9 of the hydraulic servo motor 7 is supported inside the nozzle pipe 5 via a stay vane, and the hydraulic boat 10 is connected to the output I11+8.
Alternatively, when pressure oil is supplied from the nozzle port 11, the needle 6 is moved in the axial direction via the piston 12 and the output shaft 8 to adjust the opening degree and control the flow rate of the pressure water jetted from the nozzle port. When the needle 6 is driven to open and close in this way, the needle 6
A hydraulic unbalance force acts on the As shown in Figure 3(a), this hydraulic unbalanced force acts in the self-closing direction of the needle when the needle opening is zero, that is, at and around the fully open position, and acts in the self-closing direction when the needle opening is zero, that is, at full opening and in the vicinity thereof. do. To be more specific, the hydraulic unbalance force F1 acts in the self-closing direction from the closing of the needle to the middle of the needle opening, and acts in the self-closing direction from this middle until the needle is fully opened. It gradually increases from the state, becomes a peak Pel at a predetermined opening degree near full open, then gradually decreases to zero, and then gradually increases in the self-closing direction until fully open. means that the needle valve self-closes d3 and self-opens, respectively, when the oil pressure of the revo motor 7 is lost.Therefore, the self-closing direction and the self-closing direction are the closing direction J3 and the listening direction, respectively, of the inter-needle occlusion. be.

If the oil pressure of the servo motor 5 is lost when the needle valve is fully open or close to it, the hydraulic unbalanced force F1 will drive the needle 6 in the self-closing direction and bring the needle fully open, resulting in a serious accident. There is a fear. Therefore, in order to offset this hydraulic unbalance force in the self-direction, a spring 14 is housed in the spring chamber 13 as shown in FIG. 2, and the left end of the spring 14 in the figure is Play on output shaft 8!
A spring support plate 15 is arranged. On the other hand, a spring pushing part 6a is protruded from the rear end of the needle 6, and this spring pushing part 6a acts to press the spring receiver 15 at and near the distance rU between the needles. Therefore, the spring force of this spring 14 biases the needle 6 in the direction of closing, and the spring force F2 acts only when the needle opening is fully open and around J: as shown in FIG. 3(b). However, the magnitude thereof is determined to decrease as the needle opening becomes smaller from the full needle rotation position ir1.

Because of this +iζ configuration, when the hydraulic servo motor 7 drives the needle 6 to open and close, the force acting on the servo motor 7 is the hydraulic unbalanced force F1, the spring force F2 by the spring 14, and the force shown in FIG. This is the frictional force F3 exerted on the movable part shown in C). As shown in the figure, even when B111 is operating during needle-to-needle operation, it acts in the self-closing direction over the entire range between the needles, so even if an oil pressure loss accident occurs in the hydraulic servo motor 7, the needle will always close automatically and prevent a major accident from occurring. It can be prevented.

However, in this resultant force FO, a large peak pc2 corresponding to the peak Pal of the hydraulic unbalanced force F1 occurs near the needle fully open position, so when the hydraulic nervo motor 7 opens and closes the needle 6, the driving force of the servo motor 7 is Peak value of resultant force FO during needle 17g closing operation 1:0...a
It must be set to a very large value, exceeding X. However, in the case of a servo motor with a built-in nozzle, the diameter of the servo motor is limited due to constraints in the flow path design, so in order to obtain a large driving force it is necessary to increase the operating oil pressure, which is due to the hydraulic system of the entire power plant. Exaggerate the situation and end up increasing costs.

Furthermore, since the driving force of the Nervo motor is set to exceed the instantaneous peak value F omax as mentioned above, anything other than this peak liQ FOInaX will result in wasted driving force, resulting in significant inconvenience. The economy and its movements tend to be unstable.

[Object of the Invention] Therefore, an object of the present invention is to provide a nozzle device for a Pelton water turbine that can reduce the self-closing force of the needle during operation of the needle and reduce the driving force of the servo motor. .

[I11 main point of the invention] In order to achieve this object, the present invention provides an I
0 The flow rate of pressure water to be discharged is adjusted by a needle, and this needle is driven to open and close by a hydraulic servo motor installed in the nozzle flow path. Fully open and only at close range,
A first spring that applies a spring biasing force in the opening direction to the needle, and a second spring that applies a spring biasing force in the opening direction to the needle only when the needle is fully opened and in the vicinity thereof. It is.

[Embodiments of the invention]

Hereinafter, an embodiment of a nozzle device for a Pelton water turbine according to the present invention will be described with reference to FIGS. 4 to 7, in which the same members as in FIGS. 1 to 3 are denoted by the same reference numerals. do.

4 and 5 show a nozzle device for a Pelton water turbine according to an embodiment of the present invention, and the nozzle device 4 has a nozzle pipe 5. A needle 6 movable in this direction is installed, which needle 6 is connected to an output shaft 8 of a hydraulic servomotor 7. The cylinder 9 of the revomotor 7 is supported inside the nozzle pipe 5 via a stay vane, and is equipped with a hydraulic boat 10.11,
Screws 1 to 12 are fixed to the output shaft 8. In the spring chamber 13 adjacent to the cylinder 9, there is a first spring 14.
is housed, and a spring receiver 15 fitted to the output shaft is held at the left end of the spring 14 in the figure. This spring receiver 1
5 is capable of abutting against a spring pressing portion 6a formed protruding from the rear end portion of the needle 6.

According to the present invention, the second spring 16 is incorporated between the needle side end 9a of the cylinder 9 and the piston 12, and one end of the second spring 16 is fixed to the piston 12. .

Next, the operation of installing the Pelton water turbine nozzle described above will be explained.

When the needle is fully open as shown in Figure 4,
The second spring 16 is compressed and applies a spring biasing force to the needle 6 via the piston 12 and the output shaft 8 in the direction in which the needle 6 is heard. On the other hand, when the needle is fully open, the spring pushing portion 6a is away from the spring receiver 15, so the first spring 14 does not exert any urging force on the needle 6.

In this state (when pressure oil is supplied from the hydraulic boat 11 into the cylinder 9, the needle 6 absorbs this oil pressure as shown in Fig. 6(C).
The opening degree is gradually increased by the spring force F4 of the second spring 16 shown in FIG. 6A against the hydraulic unbalance force F1 and the frictional force F3 shown in FIG. 6A. When the needle 6 reaches the middle of [;
As a result, the first spring 14 applies a spring force F2 in the opening direction to the needle 6, as shown in FIG. 6(b). The hydraulic unbalance force F1 is reversed and acts in the direction between the needles. In this way, after the middle of the summer, the needle 6 is driven by the hydraulic pressure and the hydraulic unbalance force "1" against the force F2 and the frictional force F3 of the first spring 14,
The needle is completely shaped as shown in FIG.

When moving from this fully open state to the needle closing operation, simply dissipating the hydraulic pressure from the hydraulic port 11 causes the needle 6 to be initially driven by the spring force of the first spring 14, and from the middle of the opening degree, hydraulic pressure is lost. It is driven by the balance force F1 and becomes fully open. Of course, it is also possible to supply pressure oil to the hydraulic port 10 in addition to the above-mentioned loss of oil pressure to the closing operation port 1.

The first spring 1 acts only when the needle is fully open and in the vicinity thereof.
4 and the second spring 16, which acts only in the vicinity of fully opened needle J'3 and σ, are these spring forces F2°F4 and frictional force F.
As shown in Fig. 6(e), the resultant force with the hydraulic unbalanced force F1 acts in the self-closing direction over the entire needle opening angle, and is almost constant during both the needle-to-needle operation J5 and the opening operation. It is determined that it will be the same. In particular, the second spring 16 cancels out the vicinity of the peak Pel of the hydraulic unbalance force F1.
The peak of the resultant force FO is almost lost, and there is a maximum of 1 shift FO.
max is also l+(i F
It is significantly lower than omax.

FIG. 7 shows an improved example of the above embodiment, in which all the springs 13 in FIG. 4 are not provided, and the first spring 14 is connected to the piston 12.
is arranged on the opposite side of the second spring 16 with hair length/ν. The first spring 14 is compressed by the piston 12 when the needle is fully opened and in the vicinity thereof, so it generates a spring force, but when the needle opening is in the middle, it becomes a natural length state and does not act on the piston 12 at all.

(Effects of the Invention) As is clear from the above description, according to the present invention, the force of the spring in the closing direction is applied to the needle only when the needle is fully open and in the vicinity thereof. A spring biasing force in the opening direction is applied to the opening direction, and a second spring is provided, and the hydraulic unbalanced force is offset by these spring biasing forces, and the self-closing force is made almost uniform over the entire needle opening range. The servo motor drive force can be significantly reduced and the drive can be stabilized. Furthermore, since it is a classical type using a spring, maintenance and inspection are unnecessary or extremely easy. If the spring forces of the first and second springs are set so that a self-closing force is always applied when the oil pressure of the hydraulic servo motor is lost, the pressure water can be automatically stopped when the oil pressure is lost, and large and small accidents can be prevented. At the same time, since it is only necessary to supply pressure oil to the motor while composing the needle, the control devices such as the flow valve and piping can be greatly simplified.

[Brief explanation of the drawings] Fig. 1 is a plan view showing a general Bern water turbine, Fig. 2 is a longitudinal sectional view showing a conventional servo motor with a built-in nozzle,
Figures 3 <El) to (d) are graphs showing the relationship between various external forces acting on the servo motor and the needle opening, respectively. Figures 4 and 5 are graphs showing a built-in nozzle according to an embodiment of the present invention. FIGS. 6(a) to 6(e) are vertical sectional views showing the fully open state and fully open state of the Nervo motor of the above embodiment, and graphs showing the relationship between various external forces acting on the Nervo motor of the above embodiment and the needle opening degree. FIG. 7 is a longitudinal sectional view showing a modification of the above embodiment. 4... Nozzle device, 7... Hydraulic servo motor, 16
...Second spring.

Claims (1)

[Claims] 1. A Pelton water turbine in which the flow rate of pressurized water jetted toward the runner is adjusted by a needle, and the needle is driven to open and close by a hydraulic servo motor installed in the nozzle flow path. In the nozzle device, a first spring applies a spring biasing force in the closing direction to the needle only when the needle is fully open and in the vicinity thereof, and a first spring applies a spring biasing force in the opening direction to the needle only when the needle is fully closed and in the vicinity thereof. A nozzle device for a Pelton water turbine, characterized by comprising a second spring. 2. A Pelton water turbine according to claim 1, wherein the first and second springs act on an output shaft of the hydraulic servo motor connected to the needle. nozzle device. 3. The resultant force of the first and second springs and the hydraulic unbalanced force acts in the needle closing direction over the entire needle opening range, and the value of the resultant force is greater than the frictional force when the needle is actuated. A nozzle device for a Pelton water turbine according to claim 1, wherein the spring forces of the first and second springs are determined.