Mechanical Energy Storage Device

Abstract

To provide a mechanical electricity storage device capable of safely settling a situation without causing any major damage even if an accident occurs in which the connection between a spring body and a power generation facility side is cut off. [Solution] A slider 6 is slidably housed in a cylindrical casing 4 at a longitudinal midpoint, and an expandable and contractible coil spring 2 (resilient body) is housed between the slider 6 and a fixed wall 5A (first fixed wall) closing one longitudinal end of the casing 4, and an air chamber 7 is formed between the slider 6 and the fixed wall 5A closing the other longitudinal end of the casing 4, and an orifice 8 for releasing air from the air chamber 7 is provided at a position closer to the fixed wall 5B of the air chamber 7, and the slider 6 is pulled against the fixed wall 5A to compress the coil spring 2, which is converted into physical energy and stored, and electricity is generated from the kinetic energy generated when the coil spring 2 is released and restored to its initial state.

Description

[Technical Field]

[0001] The present invention relates to a mechanical electricity storage device. [Background technology]

[0002] In recent years, research and development into renewable energy sources such as sunlight, wind, and biomass fuels has been progressing. However, this type of renewable energy is known to have large fluctuations when output as electricity via generators, etc., and does not necessarily correspond to electricity demand. Therefore, it is essential to take some measures to temporarily store surplus electricity during periods of low demand.

[0003] Until now, when such temporary storage of electricity is desired, chemical batteries such as lithium ion batteries have been used, and prior art documents relating to the power generation systems using renewable energy as described above, such as Patent Document 1 below, are already well known.

[0004] Chemical batteries such as the aforementioned lithium-ion batteries have problems such as being prone to deterioration in a short period of time and being difficult to recycle after deterioration, and there is a demand for new means of storing electricity that are different from existing chemical batteries.

[0005] More specifically, a mechanical energy storage device is being considered that uses surplus electricity to maintain a resilient body in a compressed or extended state, converts the electricity into physical energy known as the resilience of the resilient body, and temporarily stores it, and then drives a generator with the kinetic energy generated when the resilient body is released and returns to its initial state, thereby enabling electricity to be extracted. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-105667 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when attempting to convert practically sufficient electricity into physical energy and temporarily store it, it is necessary to firmly fix one end of a relatively large and long elastic body while maintaining the large restoring force generated by pushing in the other end to compress the elastic body or pulling it to extend it. Therefore, if an accident occurs in which the connection between the elastic body and the power generation equipment is severed, there is a risk that the entire equipment will be damaged by the sudden movement of the elastic body, which has become free and is trying to instantly restore itself.

[0008] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a mechanical energy storage device that can safely resolve the situation without causing major damage, even if an accident occurs in which the connection between the spring body and the power generation equipment is severed. [Means for solving the problem]

[0009] The present invention relates to a mechanical electricity storage device characterized in that a slider is slidably housed in a cylindrical casing at a longitudinal midpoint, a resilient body that can expand and contract in the longitudinal direction of the casing is housed between the slider and a first fixed wall that closes one longitudinal end of the casing, an air chamber is formed between the slider and a second fixed wall that closes the other longitudinal end of the casing when the resilient body is in a compressed state, an orifice for releasing air from the air chamber is provided at a position in the air chamber near the second fixed wall, the slider is pulled against the first fixed wall to compress the resilient body, which is converted into physical energy for storage, and electricity is generated by the kinetic energy generated when the resilient body is released and restored to its initial state.

[0010] In this case, when the slider is pulled toward the first fixed wall and the spring is held in a compressed state, electricity is temporarily stored in the form of physical energy converted into the restoring force of the spring, and when the spring is released from this stored state, electricity is generated by the kinetic energy generated when the spring returns to its initial state, and the stored electricity is extracted.

[0011] In such a mechanical energy storage device, if an accident occurs that causes the connection between the spring and the power generation equipment to be severed, the spring will become free and try to quickly restore its original shape, pushing the slider towards the second fixed wall. However, since the slider functions like a piston that draws air from the air chamber through the orifice and only a small amount of air escapes from the orifice, the air in the air chamber is compressed, creating a large resistance that hinders the movement of the slider, and the slider is prevented from moving suddenly, and moves slowly towards the second fixed wall.

[0012] In this case, the orifice is positioned at some distance from the second fixed wall, but when the slider approaches the second fixed wall, it blocks the orifice, sealing off the last of the air in the air chamber, and the remaining air functions like an air damper, reliably preventing the slider from colliding hard with the second fixed wall.

[0013] Furthermore, in implementing the present invention more specifically, it is preferable to provide a drum that winds up a cable-like body arranged between the first fixed wall and the slider to draw the slider toward the first fixed wall and compress the elastic body, a motor generator connected to the drum via a speed reducer so as to be able to transmit torque, and a brake mechanism that locks the axial rotation of the motor generator, and it is also preferable to attach an opening / closing valve whose opening can be adjusted to the orifice. [Effects of the Invention]

[0014] According to the mechanical energy storage device of the present invention, even if an accident occurs in which the connection between the spring and the power generation equipment is severed, the movement of the slider being pushed toward the second fixed wall by the spring that has become free can be suppressed by the resistance of the air in the air chamber that only gradually escapes from the orifice, allowing the slider to move slowly toward the second fixed wall, and moreover, the slider itself approaching the second fixed wall closes the orifice, causing the remaining air to function like an air damper, thereby reliably preventing the slider from strongly colliding with the second fixed wall, thereby providing the excellent effect of being able to safely resolve the situation without causing any major damage. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a side view showing an embodiment of the present invention. [Figure 2] FIG. 2 is a plan view illustrating a driving system of the drum in FIG. [Figure 3] 2 is a side view showing a state in which the coil spring of FIG. 1 is released. FIG. [Figure 4] FIG. 10 is a diagram showing an example in which an opening / closing valve capable of adjusting the opening degree is attached to an orifice. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0017] FIG. 1 is a side view showing one embodiment of the mechanical electricity storage device of the present invention. The mechanical electricity storage device 1 shown here is configured to store electricity by compressing a coil spring 2 (spring body) by pulling it with a wound wire rope 3 (cord-like body), converting the energy into physical energy, and then generating electricity from the kinetic energy generated when the coil spring 2 is released and restored to its initial state. FIG. 1 shows the stored state in which the coil spring 2 is compressed.

[0018] More specifically, a slider 6 is housed in a cylindrical casing 4 at a longitudinal midpoint so as to be freely slidable, and a coil spring 2 that can be freely expanded and contracted in the longitudinal direction of the casing 4 is housed between the slider 6 and a fixed wall 5A that closes one longitudinal end of the casing 4.

[0019] On the other hand, when the coil spring 2 is compressed (as shown in Figure 1), an air chamber 7 is formed between the slider 6 and a fixed wall 5B that closes the other longitudinal end of the casing 4, and an orifice 8 that releases air from the air chamber 7 is provided at a position closer to the fixed wall 5B in the air chamber 7.

[0020] Furthermore, a drum 9 is arranged adjacent to the fixed wall 5A outside the casing 4, which winds up the wire rope 3 arranged between the slider 6 and the drum 9 through an opening in the fixed wall 5A, thereby pulling the slider 6 toward the fixed wall 5A and compressing the coil spring 2.

[0021] The drive system for the drum 9 is as shown in the plan view of Figure 2, with one axial end of the drum 9 rotatably supported by a plummer 10 (a bearing unit that houses a rolling bearing inside) outside the casing 4, and the other end connected to a motor generator 12 via a speed increase / reduction gear 11, also outside the casing 4, so as to be able to transmit torque, and the axial rotation of the motor generator 12 is locked by a brake mechanism 13.

[0022] Here, the sides of the fixed wall 5A and the slider 6 facing each other are provided with a convex shape so that they can fit into the end of the coil spring 2 and hold the end, and a resin outer skin is attached to the body of the slider 6 so that it can slide smoothly with low friction against the inner surface of the casing 4.

[0023] It should be noted that the illustrations in Figures 1 to 4 are merely schematic illustrations for the convenience of explaining the invention, and the scale of the coil spring 2, drum 9, etc. does not necessarily correspond to the actual equipment, and it goes without saying that the casing 4 may be laid out not only horizontally but also vertically, for example.

[0024] In this case, when the motor generator 12 is driven by electricity to wind the wire rope 3 onto the drum 9, and the slider 6 is pulled toward the fixed wall 5A from the initial state shown in Figure 3 to the state shown in Figure 1 to compress the coil spring 2, and the axial rotation of the motor generator 12 is locked by the brake mechanism 13, electricity is temporarily stored in the form of physical energy, that is, the restoring force of the coil spring 2, and when the brake mechanism 13 is unlocked from this stored state, the kinetic energy generated when the coil spring 2 is released and restored to the initial state (the state shown in Figure 3) causes the wire rope 3 to be unwound from the drum 9, and the motor generator 12, which is connected to the drum 9 via the speed reducer 11 so that torque can be transmitted, is driven as a generator and electricity is extracted.

[0025] In such a mechanical energy storage device 1, if an accident occurs in which the connection between the coil spring 2 and the power generation equipment is severed due to, for example, the wire rope 3 being cut, the coil spring 2, which has become free and is trying to suddenly restore its original shape, will push the slider 6 towards the fixed wall 5B. However, since the slider 6 functions like a piston that draws the air in the air chamber 7 out through the orifice 8 and only a small amount of air escapes from the orifice 8, the air in the air chamber 7 is compressed, creating a large resistance that hinders the movement of the slider 6, and the slider 6 is prevented from moving suddenly and moves slowly towards the fixed wall 5B.

[0026] In this case, the orifice 8 is positioned at some distance from the fixed wall 5B, but when the slider 6 approaches the fixed wall 5B, it blocks the orifice 8, sealing off the last of the air in the air chamber 7, and the remaining air functions like an air damper, reliably preventing the slider 6 from strongly colliding with the fixed wall 5B.

[0027] It is possible to simply set an appropriate opening degree for the orifice 8 in advance at the design stage, but it is also possible to provide an opening-adjustable opening valve 14 as shown in FIG. 4 so that the opening degree can be adjusted as needed.

[0028] As described above, according to the above embodiment, even if an accident occurs in which the connection between the coil spring 2 and the power generation equipment side is severed due to, for example, the wire rope 3 being cut, the movement of the slider 6 being pushed toward the fixed wall 5B by the coil spring 2 which has become free can be suppressed by the resistance of the air in the air chamber 7 which only escapes little by little from the orifice 8, and the slider 6 can be slowly pushed toward the fixed wall 5B, so that the situation can be safely resolved without causing any major damage.

[0029] It should be noted that the mechanical energy storage device of the present invention is not limited to the above-described embodiments, and it is possible to use a type of spring other than a coil spring for the resilient body, and a type of rope other than a wire rope for the cord-like body, and it is also possible to arrange the cord-like body between the first fixed wall and the slider via a pulley or the like so that it moves back and forth multiple times before folding back toward the drum, and of course various other modifications can be made within the scope of the present invention without departing from the gist of the present invention. [Explanation of symbols]

[0030] 1 Mechanical energy storage device 2 Coil spring (spring) 3 Wire rope (cord) 4 Casing 5A Fixed Wall (First Fixed Wall) 5B Fixed Wall (Second Fixed Wall) 6 Slider 7 Air Chamber 8 Orifice 9 Drums 10 Plummer 11 Speed ​​increase / reduction gear 12 Motor generator 13 Brake mechanism 14 Opening and closing valve

Claims

1. a first fixed wall closing one longitudinal end of the casing and a second fixed wall closing the other longitudinal end of the casing, and an air chamber is formed between the slider and the slider when the elastic body is compressed; an orifice for releasing air from the air chamber is provided at a position near the second fixed wall in the air chamber; the slider is pulled toward the first fixed wall to compress the elastic body, thereby converting it into physical energy for storage, and the elastic body is released and restored to its initial state, thereby generating electricity.

2. 2. The mechanical power storage device according to claim 1, further comprising: a drum that winds up a cord-like body arranged between the first fixed wall and the slider to draw the slider toward the first fixed wall and compress the resilient body; a motor generator connected to the drum via a speed increase / decrease gear so as to be able to transmit torque; and a brake mechanism that locks axial rotation of the motor generator.

3. 3. The mechanical electricity storage device according to claim 1, wherein an opening / closing valve whose opening degree is adjustable is attached to the orifice.

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